Diving by a fraction is the same as multiplying by its reciprocal. In other words, we can change the division sign to multiplication and flip the second fraction.
÷
→
×

Now, we are multiplying fractions.
×

To multiply fractions, we can multiply the numerators together and the denominators together.
3 × 5 = 15
15 × 6 = 90
15 ÷ 15 = 1
90 ÷ 15 = 6
Therefore,
÷
=
