Add 21/12 and 21/80, Solve 1 9/12 + 21/80 as a fraction

Add 21/12 and 21/80

1^st number: 1 9/12, 2^nd number: 21/80

21/12 + 21/80 is 161/80.

Find the least common denominator or LCM of the two denominators:
LCM of 12 and 80 is 240

Next, find the equivalent fraction of both fractional numbers with denominator 240
For the 1st fraction, since 12 × 20 = 240,
21/12 = 21 × 20/12 × 20 = 420/240
Likewise, for the 2nd fraction, since 80 × 3 = 240,
21/80 = 21 × 3/80 × 3 = 63/240
Add the two like fractions:
420/240 + 63/240 = 420 + 63/240 = 483/240
483/240 simplified gives 161/80
So, 21/12 + 21/80 = 161/80
In mixed form: 21/80

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