Add 7/21 and 15/20
7/21 + 15/20 is 13/12.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 20 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 21 × 20 = 420,
7/21 = 7 × 20/21 × 20 = 140/420 - Likewise, for the 2nd fraction, since 20 × 21 = 420,
15/20 = 15 × 21/20 × 21 = 315/420 - Add the two like fractions:
140/420 + 315/420 = 140 + 315/420 = 455/420 - 455/420 simplified gives 13/12
- So, 7/21 + 15/20 = 13/12
In mixed form: 11/12
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