Puzzler

Go Figure

A bottle of water and a bar of chocolate cost $11.
The chocolate costs $10 more than the water. How much does the water cost?

Answer

Define the price of water as W, and the price of chocolate as C.

W + C = 11 (water plus chocolate costs 11)

C = W + 10 (chocolate is 10 more than water)

Substitute the second equation into the first, for C:

W + (W + 10) = 11

Solving, 2W = 1, or W = 50 cents. Water costs 50 cents.

(The chocolate costs 10 more, or 10.50)