Add 72/20 and 14/21, Solve 3 12/20 + 14/21 as a fraction

Add 72/20 and 14/21

1^st number: 3 12/20, 2^nd number: 14/21

72/20 + 14/21 is 64/15.

Find the least common denominator or LCM of the two denominators:
LCM of 20 and 21 is 420

Next, find the equivalent fraction of both fractional numbers with denominator 420
For the 1st fraction, since 20 × 21 = 420,
72/20 = 72 × 21/20 × 21 = 1512/420
Likewise, for the 2nd fraction, since 21 × 20 = 420,
14/21 = 14 × 20/21 × 20 = 280/420
Add the two like fractions:
1512/420 + 280/420 = 1512 + 280/420 = 1792/420
1792/420 simplified gives 64/15
So, 72/20 + 14/21 = 64/15
In mixed form: 44/15

MathStep (Works offline)

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