Problem Solving

Guys, here are the type of math worded problems I can not work out properly. "If Sam were twice as old as he is, he would be 40 years younger than Jim. If jim is 10 years younger than Sam, how old is Sam?

whodeani wrote:Guys, here are the type of math worded problems I can not work out properly. "If Sam were twice as old as he is, he would be 40 years younger than Jim. If jim is 10 years younger than Sam, how old is Sam?

is this a real problem?? i don't think the numbers are correct.

here's how i would think about it:

S = Sam
J = Jim

2S = J - 40
S = J - 10

2(J - 10) = J - 40
2J - 20 = J - 40
J = -20

what the heck??

It is a real problem. I took it out of the official guide.

i think i get the problem now...

"if Sam were twice as old as he is"

2S

"he would be 40 years younger than Jim"

2S + 40 = J

"if jim is 10 years younger than Sam"

J = S - 10

"how old is Sam?"

2S + 40 = S - 10

S = 30

what's the OA?

beatthegmat wrote:whodeani:

I recommend the Kaplan GMAT 800 book to help you prepare for math word problems. I found Kaplan's overview of words problems very helpful when I was studying for the GMAT.

Best of luck!

Hey man..i have been using Kaplan comprehensive program gmat 2006 edition..for my prep for gmat..this is the one...that i bought for my prep...

i know there are 2 more books by the name of premeir edition and the gmat 800 that ure talkin abt in the market...have i bought the wrong one for the prep...what is the difference between these..??

800guy wrote:i think i get the problem now...

"if Sam were twice as old as he is"

2S

"he would be 40 years younger than Jim"

2S + 40 = J

"if jim is 10 years younger than Sam"

J = S - 10

"how old is Sam?"

2S + 40 = S - 10

S = 30

what's the OA?

The equation does not stand. It will yield S = -50, not 30. But if we change to "he would be 40 years OLDER than Jim," then the whole thing makes sense.

Any feedback?

you're right, wtpooh. does anyone know if this question is worded correctly?

800guy wrote:i think i get the problem now...

"if Sam were twice as old as he is"

2S

"he would be 40 years younger than Jim"

2S + 40 = J

"if jim is 10 years younger than Sam"

J = S - 10

"how old is Sam?"

2S + 40 = S - 10

S = 30

what's the OA?

If 2S+40 = S-10... how is S=30? S then would be -50

This question doesnt make sense!