Add 21/60 and 54/70, Solve 21/60 + 54/70 as a fraction

Add 21/60 and 54/70

21/60 + 54/70 is 157/140.

Find the least common denominator or LCM of the two denominators:
LCM of 60 and 70 is 420

Next, find the equivalent fraction of both fractional numbers with denominator 420
For the 1st fraction, since 60 × 7 = 420,
21/60 = 21 × 7/60 × 7 = 147/420
Likewise, for the 2nd fraction, since 70 × 6 = 420,
54/70 = 54 × 6/70 × 6 = 324/420
Add the two like fractions:
147/420 + 324/420 = 147 + 324/420 = 471/420
471/420 simplified gives 157/140
So, 21/60 + 54/70 = 157/140
In mixed form: 117/140

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