Add 15/42 and 20/12
1st number: 15/42, 2nd number: 1 8/12
15/42 + 20/12 is 85/42.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 12 is 84
Next, find the equivalent fraction of both fractional numbers with denominator 84 - For the 1st fraction, since 42 × 2 = 84,
15/42 = 15 × 2/42 × 2 = 30/84 - Likewise, for the 2nd fraction, since 12 × 7 = 84,
20/12 = 20 × 7/12 × 7 = 140/84 - Add the two like fractions:
30/84 + 140/84 = 30 + 140/84 = 170/84 - 170/84 simplified gives 85/42
- So, 15/42 + 20/12 = 85/42
In mixed form: 21/42
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 30/42+20/12 15/42+40/12 15/84+20/12 15/42+20/24 45/42+20/12 15/42+60/12 15/42+20/36 75/42+20/12 15/42+20/60 15/42+20/84