Question

Wendy brought 4 cakes and 2 pies for $20. The cost of a cake is twice the cost of 1 pie. A) What was the cost of one cake b)What was the cost of 1 pie?

Answer 1

a. The cost of one cake is $4.

b. The cost of one pie is $2.

Explanation:

• Let the cost of cake be C.
• Let the cost of pie be P

C = 2P .....equation 1

4C + 2P = 20 .....equation 2

Substituting eqn 1 into eqn 2, we have;

4(2P) + 2P = 20

8P + 2P = 20

10P = 20

P = 20/10

Pie, P = $2

Next, we would determine the cost of a cake;

From equation 1;

C = 2P

Substituting the value of "P" we have;

C = 2 * 2

Cake, C = $4

Therefore, we would have the following answers;

a. The cost of one cake is $4.

b. The cost of one pie is $2.

Check:

From equation 2;

4C + 2P = 20

4(4) + 2(2) = 20

16 + 4 = 20

20 = 20