Add 15/27 and 27/42, Solve 15/27 + 27/42 as a fraction

Add 15/27 and 27/42

15/27 + 27/42 is 151/126.

Find the least common denominator or LCM of the two denominators:
LCM of 27 and 42 is 378

Next, find the equivalent fraction of both fractional numbers with denominator 378
For the 1st fraction, since 27 × 14 = 378,
15/27 = 15 × 14/27 × 14 = 210/378
Likewise, for the 2nd fraction, since 42 × 9 = 378,
27/42 = 27 × 9/42 × 9 = 243/378
Add the two like fractions:
210/378 + 243/378 = 210 + 243/378 = 453/378
453/378 simplified gives 151/126
So, 15/27 + 27/42 = 151/126
In mixed form: 125/126

MathStep (Works offline)

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