Question

3. Bhajan Singh purchased 120 reams of paper gi
at Rs. 80 per ream. He spent Rs. 280 on trans-
portation, paid octroi at the rate of 40 paise per a
ream and paid Rs. 72 to the coolie. If he wants
to have a gain of 8%, the selling price per ream
must be:
a) Rs. 86
b)Rs. 89
C)Rs. 90
d)Rs. 87.48​

Answer 1

Step-by-step explanation:

Let the time taken by 1 men alone to finish the work be x days

and the time taken by 1 boy alone to finish the work be y days then

1 men's 1 day's work= 1/x

1 boy's 1 day's work=1/y

therefore 2men's 1 days work=2/x

and 5 boys 1 days work= 5/y

since 2 men and 5 boys can together finish one work in 4 days

therefore

4(2/x+5/y)=1

2/x+5/y=1/4

again,3 men's 1 days work=3/x

and

6 boys's 1 day's work=6/y

since

3 men's and 6 boys can together finish one work in 3 days

therefore

3(3/x+6/y)=1

3/x+6/y=1/3....(1)

put 1/x=u.....(2)

and 1/y=v....(3)

then equation (1) and (2) can be rewritten as

2u+5v=1/4...(5)

3u+6v=1/3...(6)

multiplying equation (5) by 3 and equation (6) by 2 we get

6u+15v=3/4...(7)

6u+12v=2/3...(8)

subtracting, equation (8) from equation (7) we get

3v=1/12

v=1/36...(9)

substituting this value of v in equation (5) we get

u=1/18

from equation (3) and equation (10) we get

x=18

and y=36

hence the time taken by 1 men alone to finish the work is 18days and the time taken by 1 boy alone to finish the work is 36 days