Compare 70/21 and 42/80, Which fraction is greater?

Compare 70/21 and 42/80

1^st number: 3 7/21, 2^nd number: 42/80

70/21 is greater than 42/80

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 80 is 1680

Next, find the equivalent fraction of both fractional numbers with denominator 1680
For the 1st fraction, since 21 × 80 = 1680,
70/21 = 70 × 80/21 × 80 = 5600/1680
Likewise, for the 2nd fraction, since 80 × 21 = 1680,
42/80 = 42 × 21/80 × 21 = 882/1680
Since the denominators are now the same, the fraction with the bigger numerator is the greater fraction
5600/1680 > 882/1680 or 70/21 > 42/80

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