Question

Adam is 12 years older than his sister Liz. Four years ago Adam was 4 times older than his sister. How old is each now?

Answer 1

His sister is 8 and he is 20.

let's say z represents liz. we can make an equation where z+12=4z.

Solve for that and z is equal to 4. Now that was 4 years ago. She should be 8 now?

I hope this is correct because my brain isn't doing so well today.

Answer 2

Adam is 20 years old and Liz is 8 years old.

Explanation:

Let present age of Adam = x years

Let present age of Liz = y years

Now we will make the equations.

x = y + 12 -------------(1)

For second equation

( x-4) = (y-4) × 4

x-4 = 4y - 16

x = 4y + 4 - 16

x = 4y - 12 -----------------(2)

By substitution method, we substitute the value of x from equations (1) to equation (2).

y + 12 = 4y - 12

y - 4y + 12 = -12

-3y = -12 -12

3y = 24

y = 8

Now we put the value of y in equation (1)

x = 8 + 12 = 20

Therefore, Adam is 20 years old and Liz is 8 years old.