Add 72/20 and 24/21
1st number: 3 12/20, 2nd number: 1 3/21
72/20 + 24/21 is 166/35.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 20 and 21 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 20 × 21 = 420,
72/20 = 72 × 21/20 × 21 = 1512/420 - Likewise, for the 2nd fraction, since 21 × 20 = 420,
24/21 = 24 × 20/21 × 20 = 480/420 - Add the two like fractions:
1512/420 + 480/420 = 1512 + 480/420 = 1992/420 - 1992/420 simplified gives 166/35
- So, 72/20 + 24/21 = 166/35
In mixed form: 426/35
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 72/20+48/21 72/40+24/21 72/20+24/42 72/20+72/21 72/60+24/21 72/20+24/63