Greg must choose a number between 49 and 95 that is a multiple of 3, 5 and 9. Write all the numbers that he could choose. If there is more than one number, separate them with commas?
1 Answer
May 1, 2018
90
Explanation:
We should first note that any number that is a multiple of 9 is a multiple of 3. Therefore we can focus mainly on 5 and 9.
Since we also know that the number must be a multiple of 5, the available numbers must end in 5, or 0.
This gives us the numbers:
50, 55, 60, 65, 70, 75, 80, 85, 90, and 95.
90 is the only number divisible by 9, and thus divisible by 3 also.
Our answer is 90.
