Add 15/12 and 25/30, Solve 1 3/12 + 25/30 as a fraction

Add 15/12 and 25/30

1^st number: 1 3/12, 2^nd number: 25/30

15/12 + 25/30 is 25/12.

Find the least common denominator or LCM of the two denominators:
LCM of 12 and 30 is 60

Next, find the equivalent fraction of both fractional numbers with denominator 60
For the 1st fraction, since 12 × 5 = 60,
15/12 = 15 × 5/12 × 5 = 75/60
Likewise, for the 2nd fraction, since 30 × 2 = 60,
25/30 = 25 × 2/30 × 2 = 50/60
Add the two like fractions:
75/60 + 50/60 = 75 + 50/60 = 125/60
125/60 simplified gives 25/12
So, 15/12 + 25/30 = 25/12
In mixed form: 21/12

MathStep (Works offline)

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