SOLUTION: Sipho is 6 years older than Betty. In 3 years time Sipho will be twice as old as Betty. How old is Sipho now?

Click here to see ALL problems on Age Word Problems

Question 1046975: Sipho is 6 years older than Betty. In 3 years time
Sipho will be twice as old as Betty. How old is Sipho
now?

Found 2 solutions by ikleyn, ewatrrr:
Answer by ikleyn(52782)   (Show Source):
You can put this solution on YOUR website!
.
Sipho is 6 years older than Betty. In 3 years time
Sipho will be twice as old as Betty. How old is Sipho
now?
~~~~~~~~~~~~~~~~~~~~

S = B + 6, (1) S + 3 = 2*(B+3). (2) Substitute (1) into (2). You will get (B + 6) + 3 = 2*(B+3), or B + 9 = 2B + 6, or 9-6 = 2b - b, or 3 = B. Answer. Betty is 3 years old now. Sipho is 9 ears old.

There is a bunch of lessons on age word problems
    - Age problems and their solutions
    - A fresh formulation of a traditional age problem
    - Really intricate age word problem
    - Selected age word problems from the archive
    - Age problem for the day of April, 1
    - OVERVIEW of lessons on age problems
in this site.

Read them and become an expert in solving age problems.

Also, you have this free of charge online textbook in ALGEBRA-I in this site
    - ALGEBRA-I - YOUR ONLINE TEXTBOOK.

It contains a lot of other word problems and many other interesting and useful things.

Answer by ewatrrr(24785)   (Show Source):
You can put this solution on YOUR website!
Sipho is 6 years older than Betty.
Let x represent Betty's age now. Sipho then is (x+6)
in 3years...Sipho will be twice as old as Betty
(x+6) + 3 = 2(x+3)
3 = x, Betty's age now. Sipho is 9
AND
in three years..
9 + 3 = 2*6 CHECKS Sipho is twice as old as Betty