27.4k views
1 vote
Jack is 6 years older than Jill.If four years ago Jack was 3years less than twice Jill'sage, how old is Jill now?

User Acyra
by
3.2k points

2 Answers

3 votes

Answer: Jill is 13 years old

Explanation:

User Radu Coravu
by
3.6k points
3 votes

Now:

Jack= 6 + Jill's age (1)

Four years ago:

Jack - 4= (Jill's age - 4)*2 - 3 (2)

We have two equation, both for the Jack's age.

Replacing (1) in the equation (2):


(6+JillsAge)-4=(JillsAge-4)*2-3

Solving the equation for Jill's age:


\begin{gathered} 6+J\imaginaryI llsAge-4=2*J\imaginaryI llsAge-8-3 \\ 6-4+8+3=2*JillsAge-JillsAge \\ JillsAge=6-4+11=13 \end{gathered}

Answer: Jill is 13 years old now.

User Hongxu Jin
by
3.6k points