Add 54/15 and 21/40, Solve 3 9/15 + 21/40 as a fraction

Add 54/15 and 21/40

1^st number: 3 9/15, 2^nd number: 21/40

54/15 + 21/40 is 33/8.

Find the least common denominator or LCM of the two denominators:
LCM of 15 and 40 is 120

Next, find the equivalent fraction of both fractional numbers with denominator 120
For the 1st fraction, since 15 × 8 = 120,
54/15 = 54 × 8/15 × 8 = 432/120
Likewise, for the 2nd fraction, since 40 × 3 = 120,
21/40 = 21 × 3/40 × 3 = 63/120
Add the two like fractions:
432/120 + 63/120 = 432 + 63/120 = 495/120
495/120 simplified gives 33/8
So, 54/15 + 21/40 = 33/8
In mixed form: 41/8

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