Having trouble with probability problem

zethwolf:

Anna is seven years younger than Brandi. Three years from now Anna will be twice as old as Brandi was nine years ago. How old will Brandi be six years from now.

Hi zethwolf,

Let Anna's age be A years and Brandi's age be B years

A = B - 7
A+3 = 2 ( B - 9)
solve these simultaneoulsy, it is a good idea to also check your answers against the worded problem.
Once you have B you can easily work out how old Brandi will be 6 years from now.

will you be alright with the question now. Think about it for a while but then repost if you don't get it or can't finish it.

p.s. This isn't a probability question.

Am I supposed to guess the possible ages and plug them in?

zethwolf:

Am I supposed to guess the possible ages and plug them in?

No you were supposed to solve the equations simultaneously. I take it you don't know how to do that?

Let Anna's age be A years and Brandi's age be B years

A = B - 7
A+3 = 2 ( B - 9)
solve these simultaneoulsy, it is a good idea to also check your answers against the worded problem.
Once you have B you can easily work out how old Brandi will be 6 years from now.

A=B-7
Replace all the As in the second equation with B-7

B-7 +3 = 2(B-9)
B-4 = 2B-18
B - 4 - B = 2B - 18 - B
-4 = B -18
Add 18 to both sides
-4+18 = B -18 +18
14 = B

A = B-7 = 14-7 = 7
Anna is 7 and Brandi is 14
Check that these make the words correct then
it is easy to know how old Brandi will be in 6 years time.

Let me know if you still have a problem.

Thanks Melody! Problems like these always confuse me. I'll practice solving equations simultaneously :p

Guest:

Thanks Melody! Problems like these always confuse me. I'll practice solving equations simultaneously :p

You are very welcome. And, please sign up. There are lots of pluses and no minuses.