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