Add 30/80 and 60/42, Solve 30/80 + 1 18/42 as a fraction

Add 30/80 and 60/42

1^st number: 30/80, 2^nd number: 1 18/42

30/80 + 60/42 is 101/56.

Find the least common denominator or LCM of the two denominators:
LCM of 80 and 42 is 1680

Next, find the equivalent fraction of both fractional numbers with denominator 1680
For the 1st fraction, since 80 × 21 = 1680,
30/80 = 30 × 21/80 × 21 = 630/1680
Likewise, for the 2nd fraction, since 42 × 40 = 1680,
60/42 = 60 × 40/42 × 40 = 2400/1680
Add the two like fractions:
630/1680 + 2400/1680 = 630 + 2400/1680 = 3030/1680
3030/1680 simplified gives 101/56
So, 30/80 + 60/42 = 101/56
In mixed form: 145/56

MathStep (Works offline)

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