Jane must pick a number between 61 and 107 that is a multiple of 3,5,9 Write all numbers that she could choose

Question

I need help and this is due at 11:59/AM and it is 10:30/AM

Answer 1

There are two ways to solve this.

First: Writing it Out

Multiples of 3 between 61 and 107: 63, 66, 69, 72, 75, 78, 81, 84, 87, 90, 93, 96, 99, 102, 105

Multiples of 5 between 61 and 107: 65, 70, 75, 80, 85, 90, 95, 100, 105

Multiples of 9 between 61 and 107: 63, 72, 81, 90, 99

The only answer is 90.

Second: LCD w/ multiplier

The lowest common denominator of all of these numbers is 45 (what is the smallest number that can be divided by 3,5, and 9 evenly?). We thus know that the answer has to be a multiple of 45. The only answer that gives us this in the given range is 90.