Add 10/42 and 80/20, Solve 10/42 + 4 0/20 as a fraction

Add 10/42 and 80/20

1^st number: 10/42, 2^nd number: 4 0/20

10/42 + 80/20 is 89/21.

Find the least common denominator or LCM of the two denominators:
LCM of 42 and 20 is 420

Next, find the equivalent fraction of both fractional numbers with denominator 420
For the 1st fraction, since 42 × 10 = 420,
10/42 = 10 × 10/42 × 10 = 100/420
Likewise, for the 2nd fraction, since 20 × 21 = 420,
80/20 = 80 × 21/20 × 21 = 1680/420
Add the two like fractions:
100/420 + 1680/420 = 100 + 1680/420 = 1780/420
1780/420 simplified gives 89/21
So, 10/42 + 80/20 = 89/21
In mixed form: 45/21

MathStep (Works offline)

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