When we multiply two fractions, they do not have to have the same denominator like in addition or subtraction.
We simply multiply the top numbers together and then the bottom numbers together, remembering to cancel down at the end.
Multiply the numerators and the denominators together
|=||3 x 4||=||12|
|10 x 15||150|
This new fraction has a common factor of 6, we can now divide both numerators and denominators by 6.