MathDB
Ratios

Source:

March 9, 2006
ratio

Problem Statement

Given that the ratio of 3x43x-4 to y+15y+15 is constant, and y=3y=3 when x=2x=2, then, when y=12y=12, xx equals: (A) 18(B) 73(C) 78(D) 72(E) 8\text{(A)} \ \frac 18 \qquad \text{(B)} \ \frac 73 \qquad \text{(C)} \ \frac78 \qquad \text{(D)} \ \frac72 \qquad \text{(E)} \ 8