Add 21/20 and 10/42, Solve 1 1/20 + 10/42 as a fraction

Add 21/20 and 10/42

1^st number: 1 1/20, 2^nd number: 10/42

21/20 + 10/42 is 541/420.

Find the least common denominator or LCM of the two denominators:
LCM of 20 and 42 is 420

Next, find the equivalent fraction of both fractional numbers with denominator 420
For the 1st fraction, since 20 × 21 = 420,
21/20 = 21 × 21/20 × 21 = 441/420
Likewise, for the 2nd fraction, since 42 × 10 = 420,
10/42 = 10 × 10/42 × 10 = 100/420
Add the two like fractions:
441/420 + 100/420 = 441 + 100/420 = 541/420
So, 21/20 + 10/42 = 541/420
In mixed form: 1121/420

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