Question

If y varies directly as x, and x = 48 when y = 6, find y
when x = 12.

Answer 1

y = 1.5

Explanation:

Given y varies directly as x then the equation relating them is

y = kx ← k is the constant of variation

To find k use the condition x = 48 when y = 6

k =
`(y)/(x)` =
`(6)/(48)` =
`(1)/(8)`

y =
`(1)/(8)` x ← equation of variation

When x = 12, then

y =
`(1)/(8)` × 12 = 1.5