Add 21/12 and 40/8, Solve 1 9/12 + 5 0/8 as a fraction

Add 21/12 and 40/8

1^st number: 1 9/12, 2^nd number: 5 0/8

21/12 + 40/8 is 27/4.

Find the least common denominator or LCM of the two denominators:
LCM of 12 and 8 is 24

Next, find the equivalent fraction of both fractional numbers with denominator 24
For the 1st fraction, since 12 × 2 = 24,
21/12 = 21 × 2/12 × 2 = 42/24
Likewise, for the 2nd fraction, since 8 × 3 = 24,
40/8 = 40 × 3/8 × 3 = 120/24
Add the two like fractions:
42/24 + 120/24 = 42 + 120/24 = 162/24
162/24 simplified gives 27/4
So, 21/12 + 40/8 = 27/4
In mixed form: 63/4

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