Compare 21/30 and 15/40
21/30 is greater than 15/40
Steps for comparing fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 30 and 40 is 120
Next, find the equivalent fraction of both fractional numbers with denominator 120 - For the 1st fraction, since 30 × 4 = 120,
21/30 = 21 × 4/30 × 4 = 84/120 - Likewise, for the 2nd fraction, since 40 × 3 = 120,
15/40 = 15 × 3/40 × 3 = 45/120 - Since the denominators are now the same, the fraction with the bigger numerator is the greater fraction
- 84/120 > 45/120 or 21/30 > 15/40
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