## Thursday, March 10, 2011

### A Movie Casting Puzzle

Let's pretend that our master puzzle solver, KJ, is a famous Hollywood casting agent. In fact, this is precisely why she goes under the name "KJ" - it stands for Killer Jobs.

Recently a new actress contacted KJ asking to be represented by her. KJ was looking at the woman's profile picture and tried to guess how old she is. In a phone interview, she was cautious about directly asking the woman's age, so she started by sharing that she (KJ) is 30 years old and reminisced about 80's music. But the woman was mysterious about her age. The only thing she mentioned was that when she was as old as KJ is now, KJ was twice younger than what she (the woman) is now.

Can you help KJ figure out the actress's age?

Answers accepted all day long on Friday and Saturday, on our Family Puzzle Marathon. They will be hidden until Sunday morning (EST) and everyone who contributed something reasonable will get a puzzle point. Please, explain your answer.

Tom said...

Just leaped to it (which is dangerous). The actress is 40 now. When she was 30, KJ herself was 20. S'pose I should do an equation but hate doing that when I already got the answer.

John said...

The actress is 40, since that means 10 years ago KJ would have been 20. We're looking for a number so that 30 plus the number is the same as twice 30 minus the number. Twice 30 - number is 60 - twice the number, so the actress' age is 2/3 of the way from 60 to 30.

Bean said...

OK, I'm interpreting "twice younger as she what she is now" to mean "half her current age". I may not understand the grammar.

If that interpretation is right, the woman is now 40. When she was 30, KJ was 20, so half the woman's current age.

Wang said...

I solved this through algebra but you can also guess and test (a quick and dirty method when you have an idea of what to look for).

I tried the actress' age at 40.

When the actress was 30, KJ was 20 which means that KJ was twice younger than what the actress is now (40). Therefore, the actress is 40.

---------------

Algebra:

KJ = 30
M = actress age
N = some number of years ago

From the info:

M - N = 30
K - N = 1/2 (M)

subtracting the second from the first:

M - K = 30 - 1/2*M

or 3/2 M = 30 + K = 30 + 30 = 60

or M = 40

SteveGoodman18 said...

I think the mysterious actress is 40.

If we let x equal the acress's current age, then she was thirty (x-30) years ago. At that time, KJ was (30 - (x-30)) = (60 - x) years old.

So, (60 - x) = 1/2 x which means x = 40.

This makes sense, as 10 years ago, when the actress was 30, KJ would have been 20, or half the age the actress is now.

-lex- said...

She is 45 now, 15 years ago she was 30 just as old as KJ now, and KJ was 15 then, twice younger then her.

Donna said...

In response to the movie casting puzzle, the woman is 40 years old. Ten years ago, she would've been 30, and KJ would've been 20, which is half as old as 40.

Sophia said...

40 years old

Anonymous said...

The actress can't be any older than 60 yrs. since she mentioned that when she (the actress) was 30, KJ was 1/2 her current age. If the actress was any older than 60, KJ would not have been born yet.
I plugged in 40 yrs. old for the actress. 1/2 of 40 would put KJ at 20 yrs. old when the actress was 30 yrs. old. mathmover

anne-marie said...

let x be the age of KJ when the lady was 30.
let y be the age of the lady now.
we have:
(30-x)2=y/2
2x=y
by solving these equations, x=20 and y=40

Carrie said...

The woman is 40 years old.

Carrie said...

She is 40 years old.

Annie said...

Actress is 40.

Let x= # of years since actress was 30

Actress today is (30 + x), and since KJ is 30 now, she was (30 - x) when actress was 30

30-x = 1/2(30+x)
60-2x = 30+x
30 = 3x, therefore x=10. Actress is (30 + 10) = 40

Maria said...

Yes, the actress is 40 years old and almost all of you figured this out correctly. A puzzle point for Tom, John, Bean, Wang, SteveGoodman18, -lex-, Donna, Sophia, mathmover, anne-maris, Carrie and Annie.

-lex-: in your solution you got 45 as you interpreted the "twice younger than what she (the woman) is now" as twice younger than KJ,w hile it meant the actress.

On to the next puzzle!

PApaige said...

The actress is 40. When she was 30, KJ was 20.