Celine has a bottle that contains 20% of milk and the rest water. The bottle has 1 liter of water.

Write an equation in one variable that can be used to find the total number of liters of milk and water in the bottle. Define the variable used in the equation.

Celine has a bottle that contains 20% of milk and the rest water. The bottle has 1 liter of water. Let us denote x as the total number of liters of milk and water in the bottle.

(1 - 0.20) x = 1

0.8x = 1

x = 1.25 liters total number of liters of milk and water in the bottle