Track / Stage 3 / 237 of 260 #237 of 2000

Problem 237

AMC 10/12, early questions

Algebra Difficulty 3.9 Find the answer South African Mathematics Olympiad · South Africa

The number of different positive integers such that $\frac{n}{n+4} < \frac{4}{9}$ is
(A) 0
(B) 1
(C) 2
(D) 3
(E) 4

Your answer

Official solution

Multiplying gives us $9n < 4n + 16$ , i.e. $5n < 16$ , so $n = 1$ or $2$ or $3$ .

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