Compare 21/40 and 81/75, Which fraction is greater?

Compare 21/40 and 81/75

1^st number: 21/40, 2^nd number: 1 6/75

21/40 is smaller than 81/75

Find the least common denominator or LCM of the two denominators:
LCM of 40 and 75 is 600

Next, find the equivalent fraction of both fractional numbers with denominator 600
For the 1st fraction, since 40 × 15 = 600,
21/40 = 21 × 15/40 × 15 = 315/600
Likewise, for the 2nd fraction, since 75 × 8 = 600,
81/75 = 81 × 8/75 × 8 = 648/600
Since the denominators are now the same, the fraction with the bigger numerator is the greater fraction
315/600 < 648/600 or 21/40 < 81/75

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