Answer:
Case1:
Men : 30
Work : 1
Time (day×hr): 56×6 = 336 hr.
Case2:
Men : let it be m men.
Work: 1
Time: 45×7 = 315 hr.
Work being constant in both cases, men and time are in inverse proportion i.e, more men take less time.
Product of men and time is constant in both cases.
Therefore, 30×336=m×315
Or, 30×336/315 = m
Or, m = 32.
Hence, required number of men is 32.
Explanation: