Add 21/40 and 24/15
1st number: 21/40, 2nd number: 1 9/15
21/40 + 24/15 is 17/8.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 40 and 15 is 120
Next, find the equivalent fraction of both fractional numbers with denominator 120 - For the 1st fraction, since 40 × 3 = 120,
21/40 = 21 × 3/40 × 3 = 63/120 - Likewise, for the 2nd fraction, since 15 × 8 = 120,
24/15 = 24 × 8/15 × 8 = 192/120 - Add the two like fractions:
63/120 + 192/120 = 63 + 192/120 = 255/120 - 255/120 simplified gives 17/8
- So, 21/40 + 24/15 = 17/8
In mixed form: 21/8
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/40+24/15 21/40+48/15 21/80+24/15 21/40+24/30 63/40+24/15 21/40+72/15 21/40+24/45 21/40+24/75