Question

Tonya is twice Kevin's age.

In 3 years, Tonya will be 17.
How old is Kevin?
A.
6
B.
20
C.
7
D.
8

Answer 1

Hi there, Kevin's age would be C. 7. This is because Tonya right now is 14. 7 is half of 14.

Answer 2

For this case we have the following variables:

T: Tonya's age

K: Kevin's age

If Tonya is twice Kevin's age we have:

`T = 2K`

In three years Tonya will have 17, it means:

`T +3=17`

We have a system of two equations with two unknowns:

`T=2K`

`T+3=17`

From the second equation we have:
`T = 17-3 = 14`

Substituting T = 14 in the first equation we have:

`14 = 2K`

Clearing K:

`(14)/(2)=K`

So, Kevin is 7 years old

Answer:

7 years

Option C