Compare 12/15 and 21/42
12/15 is greater than 21/42
Steps for comparing fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 15 and 42 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 15 × 14 = 210,
12/15 = 12 × 14/15 × 14 = 168/210 - Likewise, for the 2nd fraction, since 42 × 5 = 210,
21/42 = 21 × 5/42 × 5 = 105/210 - Since the denominators are now the same, the fraction with the bigger numerator is the greater fraction
- 168/210 > 105/210 or 12/15 > 21/42
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