Question

V is directly proportional to the cube of (r+1) when r=1 v=24 . Work out the value of v when r=2

Answer 1

V = 81

Explanation:

Write the formula:

V = k(r + 1)^3

Substitue your numbers in

24 = k(1 + 1)^3

Work out the constant which is K

24 = k(2)^3

24 = 8k

k = 3

Now that you've found K, substitue again

V = 3 X (2 + 1)^3

V = 3 X 3^3

V = 3 X 27

V = 81