Common Denominator

Question

What is the lowest common denominator of 1/3 and 2/5.

Answer 1

15

1/3 = 5/15

2/5 = 6/15

add them to get 11/15

subtract them to get 1/15

LCD means an integer denominator common to both fractions. 30 would work too, but it's larger. Or without checking, just multiply 3 x 15 = 45, but it's also larger than the least common denominator.

15 = 3 x 5. 3 is common to both 3 and 15. take the prime factors and multiply them together. 3 and 5. 3x5=15