Add 15/21 and 1/42
15/21 + 1/42 is 31/42.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 42 is 42
Next, find the equivalent fraction of both fractional numbers with denominator 42 - For the 1st fraction, since 21 × 2 = 42,
15/21 = 15 × 2/21 × 2 = 30/42 - Likewise, for the 2nd fraction, since 42 × 1 = 42,
1/42 = 1 × 1/42 × 1 = 1/42 - Add the two like fractions:
30/42 + 1/42 = 30 + 1/42 = 31/42 - So, 15/21 + 1/42 = 31/42
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 30/21+1/42 15/21+2/42 15/42+1/42 15/21+1/84 45/21+1/42 15/21+3/42 15/63+1/42 75/21+1/42 15/21+5/42 15/21+7/42