Rosa Lena Math Solution

7/29/2019 Rosa Lena Math Solution

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July 21, 2012 [SOLUTIONS TO PROBLEMS IN PLUMBING ARITHMETIC]

1.

9500 400

5

1,820

O LC C

dL

d

d P

2.

2%

4%

6%

300,000 1

2 12

8 4

5 53

8 8

. .2 . 3 1.

1 5300000

4 8

1.875 300000

160000

:

160,000(0.06)

9600

x invested at

y invested at

z invested at

x y z eq

xx z eq

z

yy z eq

z

subst e q and eq to eq

z z z

z

z

therefore

I

I

3.

24 % 4.67%

3

1083450(0.0467)

365

48.30

i

I Pin

I

I

4.

320,000 0.11 (20,000)

12

19,450

P

P

(1 )

320,000 19,450 1

12

0.1131 11.31%

F P in

i

i or

5.

(1 )

41,090 1 0.05 3.75

34,602.10

F P in

P

P

6.

12

(1 )

5000 1 0.05

10,060.00

nF P i

F

F

7.

11

(1 )

0.06585000 1

2

59,789.96

nF P i

P

P

8.

102

(1 ) 1

0.071 1

1272,500

0.07

12

522.18

niF A

i

A

A

9.

0.10 2000

20,000

let x amount

x

x

10.

2500 150

% 100200

% 25

decrease

decrease

11.

37

(1 )

0.0775,000 1

4

142,506.52

nF P i

F

F

12.

' s in $7,5005000(0.02) 0.05 365

5300

Let x Cora come abovex

x

7500 5300

12,800

Income

Income

13.

0.06 420

7000

Let x price of the stereo

x

x

14.

2 int

5

:

2 5 120,000

8 120000

15,000

Let x building rental

x ma enance

x salaries

equation

x x x

x

x


2/4


5(15000)

75,000

salaries

salaries

15.

(1 )

15, 000 1 0.075 3.5

11,881.19

F P in

P x

P

16.

7000 0.4

2800

7000 2000

4200

overtime pay

overtime pay

regular pay

regular pay

17.

120

int 8000 0.12365

int 316

8000 316

7,684

advance erest

advance erest

Amount received

Amount received

17.

(1 )

45000 1 0.06 2.5

51,750

F P in

F x

P

18.

110 (1)

10

Q mC t

calQ g

g C

Q cal

19.0.6

1 0.0758

0.92 0.09

10

1 2 1.5

0.075 0.09 1.5

0.165 1.5

9.09

m mrate

hr hr

m mrate

hr hr

Work Work m

x x

x

x hrs

20.

362.4 (1 )

62.4

lbm lb

ft

m lb

1054.8762.4 (1)

65,824

Q mC t

JQ

lb F

Q J

21.

10,000 200(9.81)

5.10

W F x dist

dist

dist m

22.

3

2

162.4 6

12

31.2

p h

ftlbp in

ft in

lbp

ft

23.

3

.

75 62.4

1.20

sub

sub

BF Vol submerged

Vol

Vol ft

24.No change in temperature

1 1 2 2 1 2

2

32

200 15 3 15

43

PV P V where P and P are absolute pressures

V

V ft

2

2

2

307

8

38.375

38.3754

7

gpmA

gpmft

A ft

d

d ft

25.

2

3

3

225

4 12 sec

7.5 60 sec0.545

sec 1 1 min

246

Q AV

ftQ

galftQ

ft

Q gpm

26.

1 1 2 2 1 2

2

32

(

)

200 15 3 15

43

PV P V where P and P

are absolute pressures

V

V ft

27.No changes in pressure (CharlesLaw)


3/4


1 2

1 2

1

1

1 1

2

2

0 273

273

2

273

273

V V

T T

T C

T K

V V

T

T C

28.

273

6000 273

5727

C K

C

C C

29.

1

1

0

(1.0) 95(0.75)

71.25

AM

F

F lbs

30.

3

3

3

6(10)(10)

600

19.84 3.28

600 1

1.167

Vol

Vol ft

massdensity

volumekg ftdensity

ft m

kgdensitym

31.

1 1 2 2 1 2

2

32

200 15 3 15

43

PV P V where P and P are absolute pressures

V

V ft

32.

3

3

3

3

100

150

250

1001000

1000

0.0001

1001000

790

0.00019

w

a

T w a

T

m g

m g

m m m

m g

g

Vwkg

mVw m

g

Vakg

m

Va m

3

3

0.0001 0.00019

0.250.00029

862

Vt Vw Vw

Vt

massdensity

volume

kgdensitym

kgdensity

m

33.

1 1 1 1

40 30 60

24 min

combined rate individual rates

x

x

34.

1 1 1

8 12

24min

5

x

x

35.

n . min. 10 8 60 20

n . min. 5000 min

total o of

total o of

36.

2 2

.

( ) ( 5)( 4)

20

20

let x no of men and also the number of days

x x x x

x x x

x

37.

.3 . sin

2 3 70

14

let x no of double seatsx no of gle seats

x x

x

38.

1 1 1

6 4

2.4

x

x hrs

39

.

5

452.02 329

233.34

233.34 273

506.34

C

C C

K C

K K

40. Same as 37


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45.Heat loss by hot water = Heat gained

2 2

2

50(1) 70 20(1) 10

52.86

T T

T

46. same as 35

47.

12

2

6 min/

6(3)

18 min

t

t cut

time

time

48.

500 300

200

200(60 min)

min

12,000

rate inflow

rate inflow gpm

galV

V gal

49.

31

13.6 62.4 2812

13.75

p h

ftlbp in

ft in

p psi

Rosa Lena Math Solution

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