Working 12 hours per day, Raj can complete a work in 12 days. How many hours per day should he work so as to finish the same work in 9 days?
Answer & explanation
Correct answer: option 4
The formula for work is $\frac{M \times H \times D}{Work}$ = Constant
M = no. of men, H = hourse worked per day, D = no. of days
Thus, for the same man doing the same job,
Hours x Days = constant
Then, to complete the work in 9 days,
12 x 12 = Hours x 9
Hours = 16