Add 3/12 and 81/7, Solve 3/12 + 11 4/7 as a fraction

Add 3/12 and 81/7

1^st number: 3/12, 2^nd number: 11 4/7

3/12 + 81/7 is 331/28.

Find the least common denominator or LCM of the two denominators:
LCM of 12 and 7 is 84

Next, find the equivalent fraction of both fractional numbers with denominator 84
For the 1st fraction, since 12 × 7 = 84,
3/12 = 3 × 7/12 × 7 = 21/84
Likewise, for the 2nd fraction, since 7 × 12 = 84,
81/7 = 81 × 12/7 × 12 = 972/84
Add the two like fractions:
21/84 + 972/84 = 21 + 972/84 = 993/84
993/84 simplified gives 331/28
So, 3/12 + 81/7 = 331/28
In mixed form: 1123/28

MathStep (Works offline)

Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad