10 men can finish the construction of a wall in 8 days. How many men are added to finish the work in half a day

Question

option 

 

A) 160

 

B) 100

 

C) 120  

 

D) 150

 

E) 140

Answer 1

Number of men work inversely proportion to number of days to finish

 

x= number of men

y=number of day

 

y=k/x

 

8=k/10

80=k

equation is

y =80/x

 

constant =k= 80

 

so when want to finish work in 1/2 day how may men required?

 

means when y= 1/2  what is value of x

 

y=80/x

 

1/2 = 80/x

by cross multiplication

x =160

so 160 men are required to finish work in 1/2 day

 

So number of men added is 160-10=150