Add 90/20 and 24/21, Solve 4 10/20 + 1 3/21 as a fraction

Add 90/20 and 24/21

1^st number: 4 10/20, 2^nd number: 1 3/21

90/20 + 24/21 is 79/14.

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,
90/20 = 90 × 21/20 × 21 = 1890/420
Likewise, for the 2nd fraction, since 21 × 20 = 420,
24/21 = 24 × 20/21 × 20 = 480/420
Add the two like fractions:
1890/420 + 480/420 = 1890 + 480/420 = 2370/420
2370/420 simplified gives 79/14
So, 90/20 + 24/21 = 79/14
In mixed form: 59/14

MathStep (Works offline)

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