Add 10/15 and 15/21
10/15 + 15/21 is 29/21.
Steps for adding fractions
- 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,
10/15 = 10 × 7/15 × 7 = 70/105 - Likewise, for the 2nd fraction, since 21 × 5 = 105,
15/21 = 15 × 5/21 × 5 = 75/105 - Add the two like fractions:
70/105 + 75/105 = 70 + 75/105 = 145/105 - 145/105 simplified gives 29/21
- So, 10/15 + 15/21 = 29/21
In mixed form: 18/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 20/15+15/21 10/15+30/21 10/30+15/21 10/15+15/42 30/15+15/21 10/15+45/21 10/45+15/21 10/15+15/63 50/15+15/21 10/15+75/21 10/75+15/21 70/15+15/21