Question

If y is directly proportional to x, and y = 108 when x = 9, what are the values of y when x = 8 and x = 7?

A

96 and 84



B

84 and 72



C

96 and 120



D

120 and 72

Answer 1

The correct answer is (A) 96 and 84. When y is directly proportional to x, it means that the ratio of y to x remains constant. In this case, when x=9, y=108, which means that the ratio of y to x is 108/9. Since the ratio is constant, we can use that ratio to find the values of y when x=8 and x=7. When x=8, y = (108/9)x8 = 96 and when x=7, y = (108/9)x7 = 84.