Add 28/21 and 21/20, Solve 1 7/21 + 1 1/20 as a fraction

Add 28/21 and 21/20

1^st number: 1 7/21, 2^nd number: 1 1/20

28/21 + 21/20 is 143/60.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 20 is 420

Next, find the equivalent fraction of both fractional numbers with denominator 420
For the 1st fraction, since 21 × 20 = 420,
28/21 = 28 × 20/21 × 20 = 560/420
Likewise, for the 2nd fraction, since 20 × 21 = 420,
21/20 = 21 × 21/20 × 21 = 441/420
Add the two like fractions:
560/420 + 441/420 = 560 + 441/420 = 1001/420
1001/420 simplified gives 143/60
So, 28/21 + 21/20 = 143/60
In mixed form: 223/60

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