Add 56/15 and 2/21, Solve 3 11/15 + 2/21 as a fraction

Add 56/15 and 2/21

1^st number: 3 11/15, 2^nd number: 2/21

56/15 + 2/21 is 134/35.

Find the least common denominator or LCM of the two denominators:
LCM of 15 and 21 is 105

Next, find the equivalent fraction of both fractional numbers with denominator 105
For the 1st fraction, since 15 × 7 = 105,
56/15 = 56 × 7/15 × 7 = 392/105
Likewise, for the 2nd fraction, since 21 × 5 = 105,
2/21 = 2 × 5/21 × 5 = 10/105
Add the two like fractions:
392/105 + 10/105 = 392 + 10/105 = 402/105
402/105 simplified gives 134/35
So, 56/15 + 2/21 = 134/35
In mixed form: 329/35

MathStep (Works offline)

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