Add 15/30 and 21/60
15/30 + 21/60 is 17/20.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 30 and 60 is 60
Next, find the equivalent fraction of both fractional numbers with denominator 60 - For the 1st fraction, since 30 × 2 = 60,
15/30 = 15 × 2/30 × 2 = 30/60 - Likewise, for the 2nd fraction, since 60 × 1 = 60,
21/60 = 21 × 1/60 × 1 = 21/60 - Add the two like fractions:
30/60 + 21/60 = 30 + 21/60 = 51/60 - 51/60 simplified gives 17/20
- So, 15/30 + 21/60 = 17/20
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 15/30+42/60 15/60+21/60 45/30+21/60 15/30+63/60 15/90+21/60 75/30+21/60