15 men can do a work in 15 days working 8 hours a day. N men can do twice the work in 20 days working 10 hours a day. What is the value of N ?

18

Formula to be used here,

\(\frac{M_1\;×\;D_1\;×\;H_1}{M_2\;×\;D_2\;×\;H_2}\) = \(\frac{W_1}{W_2}\)

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

⇒ Putting values in the formula,

⇒ \(\frac{15\;×\;15\;×\;8}{N\;×\;20\;×\;10}\) = \(\frac{1}{2}\)

⇒ N = 18.