15 persons can fill 35 boxes in 7 days. How many persons are required to fill 65 boxes in 5 days?

The correct answer is (c) 33.

To solve this, we can use the following formula:

Number of persons required = (Number of boxes to be filled) / (Number of boxes filled per person per day) * (Number of days)

In this case, we have:

Number of boxes to be filled = 65
Number of boxes filled per person per day = 35 / 7 = 5
Number of days = 5

Therefore, the number of persons required = 65 / (5 * 5) = 33.

Option (a) is incorrect because 39 persons are more than the required number of persons.

Option (b) is incorrect because 49 persons are more than the required number of persons.

Option (d) is incorrect because 36 persons are less than the required number of persons.