Question

Suppose y varies directly with x. If y=7 when x=2, find y when x=3
A. 6/7
B. 7/6
C. 8
D. 21/2

Answer 1

\[ y=ax \text{ and } 7=a \times 2 \text{, hence } a = 3.5\]
\[so y = 3.5 \times 3 = 10.5=21/2\]
That is D