Today’s SAT question of the day: All numbers divisible by both 4 and 15 are also divisible by which of the following?

Divisibility…what does it mean?  Just that a number can be divided evenly (no remainder) by another number.  For instance, 10 is evenly divisible by 5, but not by 7.  Got it?

Good.  Let’s tackle today’s divisibility questions.

We can start by multiplying 4 and 15 together to find a common multiple – after all, if we got there by multiplying these numbers together, the product is certainly divisible by them!

4 * 15 = 60

60 isn’t an answer choice, but it’s an important step toward finding the right answer.  If all numbers divisible by both 4 and 15 will have 60 as a factor, these numbers must also have factors of 60 as their factors.

Out of the given answer choices, the only one that divides evenly into 60 is 6.

Pretty neat, huh?