Add 21/40 and 15/42
21/40 + 15/42 is 247/280.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 40 and 42 is 840
Next, find the equivalent fraction of both fractional numbers with denominator 840 - For the 1st fraction, since 40 × 21 = 840,
21/40 = 21 × 21/40 × 21 = 441/840 - Likewise, for the 2nd fraction, since 42 × 20 = 840,
15/42 = 15 × 20/42 × 20 = 300/840 - Add the two like fractions:
441/840 + 300/840 = 441 + 300/840 = 741/840 - 741/840 simplified gives 247/280
- So, 21/40 + 15/42 = 247/280
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