How many numbers can be completely divided to 240?

A student multiplies a number with 7.2 instead of 0.72. If due to this answer is 2592 more than the right answer, then what was the original number? 

Direction : What value should come in the place of question mark (?) in the following questions?

1798 ÷ 31 × ? = 348

If difference of cube and square of a number is 100 and difference of square and number is 20, then value of number is 

N is the smallest three digit prime number. When N is divided by 13, then what will be the remainder? 

If a and b are odd numbers, then which of the following is even?

Find the average of all prime numbers from 1 to 20?

Direction: What is the approximate value will come in place of the question mark(?) in the following questions?
5682 ÷ 63 × 36=? ×19