FY Math / Analytical Reasoning 101 September 30 th, 2010.
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Transcript of FY Math / Analytical Reasoning 101 September 30 th, 2010.
FY Math / Analytical Reasoning 101September 30th, 2010
Roadmap Math 2
Agenda
• Roadmap check-in• Case analysis overview• Sample case demonstration• Case math: a structured approach• Calculation best practices• Practice Time
9/30/10
Roadmap Math 3
Now is a great time to research firms and work on distinguishing yourself
Sep Oct Nov Dec Jan Feb
Targeted
Exceptional
Analytical
Mature
Presentations
Networking events
Resume drops
Interviews
T.E.A.M.Model
RecruitingEvents
• Vault/Wetfeet/company website research
• Informal conversations w/ second years
• Refining resumes with SY consultants
• Behavioral interview practice w/ CMC
• Case 101• Math review session (today)
Targeted Exceptional Analytical
Today
9/30/10
Roadmap Math 4
Your Roadmap to a consulting position
• Oct 4-7: Case Team Prep Unit 1: Behavioral
• Oct 5th: Week in cities / Networking event 6:30pm
• Oct 21-22: Week-In-Cities
• Informal case prep with classmates
• Deloitte Case Challenge• David Ohrvall Case Prep
Workshop• National case competitions
• Be prepared• Be engaged• Complete short feedback
surveys after events• Contact a member of the
Roadmap team if you have any questions
These DMCC events will facilitate your preparation for consulting interviews
Upcoming events Case Prep Opportunities Expectations
9/30/10
Roadmap Math 5
Today’s session covers the basics of analytical reasoning and how math appears in cases
January (Interviews)
9/30/10
InterviewFoundation
October
Acc
ount
ing
&
Fin
ance
Confidence& Composure
SubjectAreas
FineTuning
Fall 1
Fall 2
Hypothesis Based Problem Solving (Case Basics)
Analytical Reasoning (Math)
Eco
nom
ics
Str
ateg
y
Mar
ketin
g
“Telling Your Story” (Behavioral)
Case Interview feedback formCase _______________________ Case type ______________ Interviewer ____________________
Execution
• Structure Logical approach MECE Appropriate drive to solution
• Quantitative Ability Speed Accuracy Comfort, reaction to mistakes
• Business intuition Practical Insightful Breadth & depth across multiple functions Creativity
1 2 3 4 5Comments:
1 2 3 4 5Comments:
1 2 3 4 5Comments:
Communication
• Professionalism Poise Confident-Persuasive Articulate-concise Client ready
• Written Clarity of writing and page layout Ability to refer back Comfort, reaction to mistakes
1 2 3 4 5Comments:
1 2 3 4 5Comments:
Case start time __:__
Case end time ___:____
Framework development ______ minFramework explanation ______ minCase discussion ______ min
Behavioral (optional)
• Quality of star stories 1 2 3 4 5 Comments: • Length 1 2 3 4 5• Clarity 1 2 3 4 5• Relevance 1 2 3 4 5
Strengths
Weaknesses
Overall Rating: 1 2 3 4 5
Key: 1=Bottom 10%, 2= 10th-25th percentile, 3= middle 50%, 4= 75th-90th percentile, 5=Top 10%
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Roadmap Math 7
Agenda
• Roadmap check-in• Case analysis overview• Sample case demonstration• Case math: a structured approach• Calculation best practices• Practice Time
9/30/10
Roadmap Math 8
Consultants use math analysis to develop solutions to ambiguous problems
ID key numbers & quantify the
situation
Problem /Ambiguity
Problem /Ambiguity
Use #s/analytics to develop projections
Develop problem insights using the
answer & #s
9/30/10
Roadmap Math 9
Case interviews assess a candidate’s ability to use analysis to solve the business problem
ID key numbers & quantify the
situation
Problem /Ambiguity
Problem /Ambiguity
Use #s/analytics to develop projections
Develop problem insights using the
answer & #s
Does the candidate: • Develop a good
approach to reduce complexity
• Understand when numeric analysis is necessary
Does the candidate: • Tie the numbers back to
the big picture• Develop insights into
the problem
Does the candidate: • ID key numbers• Choose the right level of
granularity• Make sound
assumptions about missing numbers
Does the candidate: • ID appropriate analysis• Have a structured math
approach• Show comfort w/
numbers and calculations
9/30/10
Roadmap Math 10
Agenda
• Roadmap check-in• Case analysis overview• Sample case demonstration• Case math: a structured approach• Calculation best practices• Practice Time
9/30/10
Roadmap Math 11
Example case: Smile-Bright toothpaste
Your client, Smile-Bright toothpaste has decided that selling electronic toothbrushes would be a great way to increase sales of it’s toothpaste; however, they only want to do this if the electronic toothbrushes can be
profitable on their own. How would you advise them?
9/30/10
Roadmap Math 12
Agenda
• Roadmap check-in• Case analysis overview• Sample case demonstration• Case math: a structured approach• Calculation best practices• Practice Time
9/30/10
Case math is generally simple arithmetic
• General Arithmetic (addition, subtraction, multiplication, division)
• Ability to keep track of numbers of different magnitudes
• Use percents, fractions, proportions
• Decipher graphs / charts / diagrams
• Calculus
• Full discount cash flow analysis
• Complex finance formulas / techniques
• Accounting ratios
• Black-Schole’s ratio (see cover slide)
Definite interviewee expected
skill-setGenerally not expected*
* Exceptions:• Every firm is a little different. Make to sure to
follow up with second years/firm representatives late in Term 2 to see the differences
Example Exceptions• ZS: Derivatives• LEK: Some finance/valuation math• Deloitte: Financial ratios
Like a case, the analytics should be structured
Identify if analytics are needed • Every case doesn’t need math, work with the interviewer to determine if mathematical analysis is needed
Structure approach • Start by developing a structure/game-plan for analysis (To calculate expected profit I am going to subtract our total costs from our projected revenue)
• Review the approach with the interviewer
Gather key numbers (estimate missing numbers)
• After identifying the key numbers you need in your structure ask your interviewer if they have them
• If not, ask if an estimation would be appropriate
Calculate • Work out the problem by fitting the numbers into the structure you outlined, checking in with the interviewer every few steps
Check work • Look over your work and perform a sanity check to see if everything makes sense
Fit in big picture • Place the information back into the context of the case and determine next steps
At no point should an interviewee go heads down or silent for more than 15-20 seconds. Analysis should be an interactive process
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2
3
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5
6
A structured approach provides a framework for sound analytics
ID key numbers & quantify the
situation
Problem /Ambiguity
Problem /Ambiguity
Use #s/analytics to develop projections
Develop problem insights using the
answer & #s
1
2
3
4
5
6
Identify if analytics are needed
Structure approach
Gather key numbers (estimate missing #s)
Calculate
Check work
Fit in big picture
A structured math approach will help candidates of all analytical abilities
• Keeps the focus on describing analysis instead of doing analysis
• Demonstrates the ability to tie numbers back to the big picture
• Keeps a candidate from getting too deep into the numbers
• Helps a candidate show analytical skill even if mistakes are made in computation
• Keeps numbers organized, making calculations easier
• Simplifies math
Benefits for those who are “strong” at math
Benefits for those who are “weak” at math
A good practice for good “casing” is to always explain what you are going to do before you do it, and walk your interviewer what you’re doing every step of the way
The price per standard room on a cruise ship is $560/week The RowBoat Luxury Shipping Company has the following
assets: 3 fleets of luxury cruise boats Each fleet has 15 ships Each ship has on average 5 decks Each deck has on average 60 rooms How much does RowBoat make per day?
3 fleets* 15 ships/fleet * 5 decks/ship* 60 rooms/deck * 560= $7.56M 3 fleets* 15 ships/fleet * 5 decks/ship* 60 rooms/deck * $80/day= $1.08M
Common Math Mistakes
Miscount the Zeros!
Mistake Example
Johnny’s Apple Company sold 20M barrels of seed in 2010 Each barrel has 100 seeds Therefore Johnny’s Apple Co. sold:
20,000,000*100 or 200M seedsWRONGRIGHT
Confuse terms
WRONG
RIGHT
20,000,000*100 or 2000M or 2B seeds
Calculate the payback period if a machine costs $260,000 and the total lifetime revenue for the machine is $30,000/year
Simplify, then divide. 260,000/30,000= 26/3 (much easier) 3 goes into 24- 8 times with 2 remaining. So the answer is 8 and two thirds!
Common Math Mistakes
Silent math
Mistake Example
What is the average revenue per elderly customer? (Silence)
I don’t do division
WRONG
RIGHT
WRONG
Talk through each step! “You mentioned elderly customers make up 2/3 of total
customer base but 1/3 of total revenue. With a total customer base of 1M, that means there are ~.67M elderly customers. Total revenues are 50M. If revenues were 100M, elderly revenues would be 33M. Since revenues are 50M, or half of 100M, elderly revenues are half of 33M, or around 16.67M. That means average revenue per customer is 16.67/..67. To put this in easier terms, lets multiply be 3/2 rather than divide by 2/3. So 16.67 divided 2 is 8.33, then times 3 equals 25. So average revenue per elderly customer is $25”
“I should divide 260,000 by 30,000, but I didn’t practice division. How about another question?”
RIGHT
Smile-Bright breakdown
Identify if analytics are needed
• Math analysis needed to estimate revenue
• Math analysis need to scope costs
Structure approach • Demand = US population * Health conscious individuals * % with enough disposable income * electronic toothbrush purchases per year
• Cost = FC + VC
Gather key numbers (estimate missing numbers)
• Health conscious individuals = 60%• Average electronic toothbrush lasts 5
years• Average price is 30$• Estimated level of wealthy individuals,
US pop
• Recorded costs for:• US rollout• Setup costs• Materials• Labor• Taxes• Transportation
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2
3
Potential Revenue Cost structure
Smile-Bright breakdown
Calculate • 300M * 2/3 * 1/4 * 1/5 = 10m p.a.• 10m * 1/10 addr market = 1m potential
customers• 1m * $30 = $30,000,000
• China: 5M + 3M + 1M*(5 + 4 + 1+ 15) = 33Million
• Mexico: 5M + 1M + 1M*(6 + 5 + 2 + 10) = 29M
Check work • 30 million is about 10 cents for every American, that sounds about right
• 29 million dollars is around the right magnitude, this number looks good
Fit in big picture • $30,000,000 in total revenue sounds shows that this presents a sizeable opportunitiy
• Overall, Mexico has the better cost structure and is the only option that would allow for a profitable roll-out
Potential Revenue Cost structure
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6
Roadmap Math 21
Agenda
• Roadmap check-in• Case analysis overview• Sample case demonstration• Case math: a structured approach• Calculation best practices• Practice Time
9/30/10
Percents and fractions are very common in case interviews
• Get comfortable converting between percents, #/100 or #/1000 and fractions
• Ask a friend to quiz you
.75 = 75% = 75 out of 100 = 3/4
.33 = 33% = 33 out of 100 = 1/3
4 Calculation Best Practices
TIP
S
Roadmap Math 23
Interviewees can represent numbers in any way, but are best served to be consistent
Good: 1M, .01M, 20M
Caution: 1,000,000, 10K, 20M
4 Calculation Best Practices
• Use whatever feels natural but your best to keep it consistent• Be ready for a mix of millions, billions, and thousands find an
approach that works for youTIP
S
9/30/10
Roadmap Math 24
Case math can greatly simplify if you choose the correct units
Good: $ / cubic feet / mile
Caution: $ / boat
4 Calculation Best Practices
• Think small: what is the smallest unit of comparison you can use to compare all the different options
• Look out for units involving: time (per year), weight (kg, pound), distance (miles), etc…
TIP
S
9/30/10
Roadmap Math 25
Rounding may be used to simplify complex math
Good: 1.37*66% = 1.5*2/3 = 1
Caution:1.4*66% =lots of math
4 Calculation Best Practices
• Always ask your interviewer if you can round!• Don’t be afraid to ask though and use it to your advantage• Don’t ask to round easy numbers (75% 100%)T
IPS
9/30/10
Roadmap Math 26
Distilling case problems into formulas shows structure and allows for graphing
Cost = FC + VC * Q
$1m
$3m
Num of toothbrushes
Mexico
China
4 Calculation Best Practices
9/30/10
Tables are very useful for keeping track of numbers and details
Materials 5 $ / unit 6 $ / unit
Labor 4 $ / unit 5 $ / unit
Taxes 1 $ / unit 2 $ / unit
Transportation 15 $ / unit 10 $ / unit
Total Var costs 25 $ / unit 23 $ / unit
US Rollout $4,000,000 $4,000,000
Setup costs $3,000,000 $1,000,000
Total fixed cost $7,000,000 $5,000,000
Manufacture in China Manufacture in Mexico
4 Calculation Best Practices
• Whenever there are multiple options think table!• Write big on the paper, keep your number legible
TIP
S
Other tips: Division and Multiplication decomposition
• Use decomposition to “cross-out” numbers in the numerator / denominator
Example:
72 / 16= (8 * 9) / (8 *2)= 9 / 2
• Use mathematical decomposition to speed up multiplication
Example:
72 * 8= 70*8 + 8*8= 420 + 64 = 484
Division decomposition Multiplication decomposition
Keep your eyes out for other tips while working with students
Other tips: Rule of 72 & Averages
• The amount of periods it takes to double a number is 72 divided by the rate
Example:
How long will it take to double $5 if the annual interest rate is 9%
= 72/9 = 8 years
• Watch out for averages they are trickier than they appear
Examples:
Average cost of items at a retailer
Average effectiveness of a drug
Rule of 72 Averages
Keep your eyes out for other tips while working with students
Other tips: 1% and 10% rule
• When faced with tough percentages, put things in terms of 10%, 5%, and/or 1%
Example: LifeJacket Ventures makes 17%
margins on revenue of $88M. How much profit do they make?
= 10%= 8.80 5%= 4.40 1%= 0.88 1%= 0.88= 14.96M (yeah addition!)
1% rule
Simplify whenever possible
• 10% rule: drop the last digit
Example: 10% of 156= 15.6• 20% rule: drop last digit and double the
number
Example: 20% of 16,300= 1630*2= 3260• 25% rule: half the number twice
Example: 25% of 244M= 122M (50%) = 61M (25%)
10, 20, 25% rule
Other tips: % of round numbers and division simplification
• When calculating percentages of round numbers:
x% of y = y% of x
Example: Cabinet Pro LLC has profits that are
28% or sales of $400,000. What are CP’s profits?
= 28% of 400,000= 400,000% of 28
• Simplify to 4000*28 and then 4*28• 4*28= 112
• Then add back the zeros• $112,000
% of round numbers
Simplify whenever possible
• Simplify tough division questions by splitting the division into two easier steps
Example: • One step: 960/6 = not fun
• Two step: • 960/2= easier (480)• 480/3 = also easy (160)• Answer = 160!
Division simplification
Roadmap Math 32
Agenda
• Roadmap check-in• Case analysis overview• Sample case demonstration• Case math: a structured approach• Calculation best practices• Practice Time
9/30/10
Roadmap Math 33
Practice TimeYou are the captain of your first year campout team. Despite many requests, you have limited your team to 20 people. You are traveling to Costco to purchase beer and water for the weekend. You received the following data from informed second years: •Begins on Friday at 7pm and goes to Sunday at 7am•Average beer consumption: 1.5 beers/hour/person• Each beer has 12 ounces and comes in cases of 24 beers• Due to the new campout rules, you must have 2 ounces of water per ounce of beer•Each water bottle has 20 ounces and comes in packages of 12
How many cases of beer and how many packages of waters do you need to buy?!
9/30/10
Roadmap Math 34
Practice TimeYour client wants to commercialize a new chemical that improves the quality of apples. What is the maximum price the charge for a hectoliter of the chemical?
• Market = Maine• Maine = 800 orchards• Average orchard = 100 acres• Average revenue =$30,000 / orchard• 25% of revenue is full apples• 75% of revenue comes from juice• The chemical improves apple yield by 10% and juice yield by 5%• Each hectoliter can cover 200 acres
9/30/10