Add 15/20 and 7/42
15/20 + 7/42 is 11/12.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 20 and 42 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 20 × 21 = 420,
15/20 = 15 × 21/20 × 21 = 315/420 - Likewise, for the 2nd fraction, since 42 × 10 = 420,
7/42 = 7 × 10/42 × 10 = 70/420 - Add the two like fractions:
315/420 + 70/420 = 315 + 70/420 = 385/420 - 385/420 simplified gives 11/12
- So, 15/20 + 7/42 = 11/12
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 30/20+7/42 15/20+14/42 15/40+7/42 15/20+7/84 45/20+7/42 15/20+21/42 15/60+7/42 75/20+7/42 15/20+35/42 15/20+49/42