Add 21/12 and 21/20, Solve 1 9/12 + 1 1/20 as a fraction

Add 21/12 and 21/20

1^st number: 1 9/12, 2^nd number: 1 1/20

21/12 + 21/20 is 14/5.

Find the least common denominator or LCM of the two denominators:
LCM of 12 and 20 is 60

Next, find the equivalent fraction of both fractional numbers with denominator 60
For the 1st fraction, since 12 × 5 = 60,
21/12 = 21 × 5/12 × 5 = 105/60
Likewise, for the 2nd fraction, since 20 × 3 = 60,
21/20 = 21 × 3/20 × 3 = 63/60
Add the two like fractions:
105/60 + 63/60 = 105 + 63/60 = 168/60
168/60 simplified gives 14/5
So, 21/12 + 21/20 = 14/5
In mixed form: 24/5

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