Question

if n is the largest two digit nuber that can be expressed as the product of two prime numbers greater than 3, what is the value of n?

Answer 1

List of the first few prime numbers greater than 3:

5, 7, 11, 13, 17, 19, 23, 29

Now find the combination that you can multiply and still have a 2 digit number:

5 x 7 = 35

5 x 11 = 55

5 x 13 = 65

5 x 17 = 85

5 x 19 = 95

5 x 23 = 115 ( 3 digit number, can't use).

7 x 5 = 35

7 x 11 = 77

7 x 13 = 91

7 x 19 = 133 ( 3 digit number, can't use).

The largest 2 digit number would be 5 x 19 = 95