Question

Which ratio is equivalent to start fraction 3 over 7 end fraction? A. 6 to 10 B. 9:21 C. start fraction 12 over 35 end fraction D. 7 to 3

Answer 1

B. 9 : 21

Explanation:

Multiply numerator and denominator by 3:

... 3/7 × 3/3 = 9/21 ⇒ 9 : 21

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Any denominator that is not a multiple of 7 will not work. 35 is a multiple of 7 (=5×7), but 12 (=4×3) is not the same multiple of 3.