Let the contractor's capital be c and his weekly sum of be x
Let payment needed for one man one week = m
His own capital together with the weekly sum enables him to pay 42 men for 52 weeks
c + 52x = 42m * 52 = 2184 m ---(1)
If he had 60 men and the same wages, his capital and weekly sum would suffice for 13 weeks
c+13x = 60m*13 = 780m ---(2)
(1)-(2) => 39x = 1404 m
x = 36 m ---(A)
Substituting this value in (2),
c + 13 * 36 m = 780m
c = 312 m ---(B)
Let n men can be maintained for 26 weeks.
c + 26x = nm * 26
Substituting the values of c and x in the above equation from (A) and (B)
312 m +26 * 36m =nm * 26
1248 m = 26nm
1248 = 26n
then
n = 1248 /26
= 48