Add 1/15 and 21/42
1/15 + 21/42 is 17/30.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 15 and 42 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 15 × 14 = 210,
1/15 = 1 × 14/15 × 14 = 14/210 - Likewise, for the 2nd fraction, since 42 × 5 = 210,
21/42 = 21 × 5/42 × 5 = 105/210 - Add the two like fractions:
14/210 + 105/210 = 14 + 105/210 = 119/210 - 119/210 simplified gives 17/30
- So, 1/15 + 21/42 = 17/30
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 2/15+21/42 1/30+21/42 1/15+21/84 3/15+21/42 1/15+63/42 1/45+21/42 5/15+21/42 1/75+21/42 7/15+21/42