Question

A team of friends planned to finish a construction work in 60 days. Out of them, 5 friends couldn’t come and the job was finished in 80 days. What was the total number of friends in the starting

Answer 1

Hi ,

Number friends worked is indirectly

proportion to number of days for

finishing the same work.

Let number of friends worked = x

Number of days to finish the work = y

x y = k ( k is a constant )

According to the given problem ,

x 1 = x ( number of friends started the

work )

y1 = 60 days ,

x2 = ( x - 5 ) ,

y2 = 80 days

x1 × y 1 = x2 × y2

x × 60 = ( x - 5 ) × 80

60x = 80x - 400

60x - 80x = -400

-20x = -400

x = ( -400 )/ ( -20 )

x = 20

Number of friends started the work

= x = 20

I hope this helps you.