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Mathematics>Standard Multiple Choice

Read the following SAT test question and then click on a button to select your answer.
If 24/15 = 4/n, what is the value of 4n?

(A) 6
(B) 10
(C) 12
(D) 30
(E) 60

答案和解析

答案：B

解析：

Multiplying both sides of the equation 24/15 = 4/n by 15 n gives (15n) (24/15) = (15n) (4/n), which simplifies to 24n = (15) (4) = 60. Dividing both sides of the equation 24n = 60 by 6 gives (24n)/6 = 60/6, and so 4n = 10.