Compare 20/21 and 18/20
20/21 is greater than 18/20
Steps for comparing fractions
- 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,
20/21 = 20 × 20/21 × 20 = 400/420 - Likewise, for the 2nd fraction, since 20 × 21 = 420,
18/20 = 18 × 21/20 × 21 = 378/420 - Since the denominators are now the same, the fraction with the bigger numerator is the greater fraction
- 400/420 > 378/420 or 20/21 > 18/20
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