Choose a number between 55 and 101 that is a multiple of 5,10,15

In order to calculate multiples of 5, 10, 15, we need to find their LCM. Their LCM would be 30, so their multiples would be: 30, 60, 90, 120

Here, 60 and 90 both are in between 55 and 101. So, both of them can be your answer

Hope this helps!