Compare 20/21 and 72/80
20/21 is greater than 72/80
Steps for comparing fractions
- 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,
20/21 = 20 × 80/21 × 80 = 1600/1680 - Likewise, for the 2nd fraction, since 80 × 21 = 1680,
72/80 = 72 × 21/80 × 21 = 1512/1680 - Since the denominators are now the same, the fraction with the bigger numerator is the greater fraction
- 1600/1680 > 1512/1680 or 20/21 > 72/80
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