Question

Direct Variation: If y = 12, when x = 4, find y when x = 20. a.40 b.48 c.12 d.60

Answer 1

d

Explanation:

Given the x and y are in direct variation then the equation relating them is

y = kx ← k is the constant of variation

To find k use the condition y = 12 when x = 4, that is

12 = 4k ( divide both sides by 4 )

3 = k

y = 3k ← equation of variation

When x = 20 , then

y = 3 × 20 = 60 → d