Question

The number of apples required to bake a pie varies directly with the square of the diameter of the pie tin. If 4 apples are required for a pie tin with a diameter of 8 inches, how many apples are required for a pie tin with a diameter of 10 inches?

Answer 1

5 apples

Explanation:

Solution,

4 apples are required for a pie tin with a diameter of 8 inches

For 1 inch of the pie tin 8/4=2 apples are required.

For 10 inches 10/2=5 apples are required.

Answer 2

• 6.25 apples

Explanation:

Let the number of apples be a and diameter be d.

The relationship is:

• a = kd², where k is he coefficient of proportionality

We have a = 4 when d = 8.

Find k:

• 4 = k*8²
• 4 = 64k
• k = 4/64
• k = 1/16

The equation is now:

• a = d²/16

Find a when d = 10:

• a = 10²/16
• a = 100/16
• a = 6.25 apples