Add 3/21 and 75/28, Solve 3/21 + 2 19/28 as a fraction

Add 3/21 and 75/28

1^st number: 3/21, 2^nd number: 2 19/28

3/21 + 75/28 is 79/28.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 28 is 84

Next, find the equivalent fraction of both fractional numbers with denominator 84
For the 1st fraction, since 21 × 4 = 84,
3/21 = 3 × 4/21 × 4 = 12/84
Likewise, for the 2nd fraction, since 28 × 3 = 84,
75/28 = 75 × 3/28 × 3 = 225/84
Add the two like fractions:
12/84 + 225/84 = 12 + 225/84 = 237/84
237/84 simplified gives 79/28
So, 3/21 + 75/28 = 79/28
In mixed form: 223/28

MathStep (Works offline)

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