Add 21/42 and 15/40
21/42 + 15/40 is 7/8.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 40 is 840
Next, find the equivalent fraction of both fractional numbers with denominator 840 - For the 1st fraction, since 42 × 20 = 840,
21/42 = 21 × 20/42 × 20 = 420/840 - Likewise, for the 2nd fraction, since 40 × 21 = 840,
15/40 = 15 × 21/40 × 21 = 315/840 - Add the two like fractions:
420/840 + 315/840 = 420 + 315/840 = 735/840 - 735/840 simplified gives 7/8
- So, 21/42 + 15/40 = 7/8
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