Question

The variable z is directly proportional to x. When x is 15, z has the value 165. What is the value of z when x = 25?

Answer 1

275

Explanation:

z is directly proportional to x:

z = kx

When x is 15, z is 165.

165 = k × 15

k = 11

When x = 25:

z = 11 × 25

z = 275

Answer 2

z=275

Explanation:

it has a ratio 1:11

that must be it