Question

Able has a younger sister and an older brother.

- Able’s age can be represented by x.
- Able’s sister is 4 years younger than him.
- Able’s older brother is twice as old as he is.
- The combined age of all three siblings is 32.

How old is Able’s younger sister?

9 years

13 years

5 years

3 years

Answer 1

5 years

Explanation:

1. if able's age is x, then his sister's is x-4, and his brother's is 2x

2. if these sum to 32, then we can formulate the equation x+(x-4)+2x=32

3. now solve for x, 4x-4=32, 4x=36, x=9

4. if able's sister is x-4 years old, she is 9-4, or 5 years old