Question

Mary is twice older than her sister in 5 years time she will be 2 years older than her sister find how old are they both now

Answer 1

Define x:

Let her sister be x.

Sister = x

Mary = 2x

.

In 5 years time:

sister = x + 5

Mary = 2x + 5

.

In 5 years time, Mary is 2 years older than her sister:

2x + 5 = (x + 5) + 2

.

Solve x:

2x + 5 = (x + 5) + 2

2x + 5 = x + 5 + 2

2x + 5 = x + 7

x = 2

.

Find their age:

Sister = x = 2

Mary = 2x = 2(2) = 4

.

Answer: Mary is 4 years old and her sister is 2 years old.