A contractor takes a contract to complete a road in 60 days and employed 70 labours. After 25 days, he found that one fourth of work is completed. How many more labours he requires to complete the remaining work in time?

80

Formula to be used here,

⇒ \(\frac{M_1\;×\;D_1}{M_2\;×\;D_2}\) = \(\frac{W_1}{W_2}\)

where, M = No. of Men, D = No. of Days, W = Work,

⇒ Putting in the values,

⇒ \(\frac{70\;×\;25}{(M + 70)\;×\;35}\) = \(\frac{1/4}{3/4}\)

⇒ M + 70 = 150,

⇒ M = 150 - 70 

⇒ M = 80,

Therefore, 80 men more are needed to complete the remaining work in time.