Add 21/60 and 27/15, Solve 21/60 + 1 12/15 as a fraction

Add 21/60 and 27/15

1^st number: 21/60, 2^nd number: 1 12/15

21/60 + 27/15 is 43/20.

Find the least common denominator or LCM of the two denominators:
LCM of 60 and 15 is 60

Next, find the equivalent fraction of both fractional numbers with denominator 60
For the 1st fraction, since 60 × 1 = 60,
21/60 = 21 × 1/60 × 1 = 21/60
Likewise, for the 2nd fraction, since 15 × 4 = 60,
27/15 = 27 × 4/15 × 4 = 108/60
Add the two like fractions:
21/60 + 108/60 = 21 + 108/60 = 129/60
129/60 simplified gives 43/20
So, 21/60 + 27/15 = 43/20
In mixed form: 23/20

MathStep (Works offline)

Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad