Compare 20/21 and 42/45
20/21 is greater than 42/45
Steps for comparing fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 45 is 315
Next, find the equivalent fraction of both fractional numbers with denominator 315 - For the 1st fraction, since 21 × 15 = 315,
20/21 = 20 × 15/21 × 15 = 300/315 - Likewise, for the 2nd fraction, since 45 × 7 = 315,
42/45 = 42 × 7/45 × 7 = 294/315 - Since the denominators are now the same, the fraction with the bigger numerator is the greater fraction
- 300/315 > 294/315 or 20/21 > 42/45
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