Question

Dana is 20 years younger than her mother. In 4 years, the mother will be twice as old as Dana. How old is the mother now? (Strategy)

Answer 1

mother is 36 years old

Explanation:

let x be the mother's age , then Dana is x - 20 ( 20 years younger )

In 4 years

mother is x + 4 and Dana is x - 20 + 4 = x - 16

At this time the mother is twice as old as Dana , that is

x + 4 = 2(x - 16)

x + 4 = 2x - 32 ( subtract x from both sides )

4 = x - 32 ( add 32 to both sides )

36 = x

Then the mother is 36 years old