SAT Maths Practice Question. Help!

In 10 years, Bob will be twice as old as he was 7 years ago. How old is he now?

word help question problem math sat

asked Aug 12 '11 at 15:53

LilJonsonG
1●3●3●4

edited Aug 12 '11 at 16:04

Mattophobia ♦♦
7.0k●73●122●206

Maths? Isn't math?

(Aug 12 '11 at 21:57) DJ Scooby Doo

Both are widely-used forms. It's usually "math" in the U.S. and "maths" over in the U.K. and Europe.

(Aug 12 '11 at 22:00) eddieringle

I learned something new today! Thanks @eddieringle

(Aug 12 '11 at 22:02) DJ Scooby Doo

you learned english instead math here? :)

(Aug 12 '11 at 22:06) Ivan Tomica

lmfao, yep

(Aug 12 '11 at 22:10) DJ Scooby Doo

you guys are par excellence...

(Aug 12 '11 at 22:45) Ivan Tomica

showing 5 of 6 show all

2 Answers:

oldest newest most voted

24, cause 10+7= 17 17x2=34 34-10=24. my opinion :)

answered Aug 12 '11 at 16:07

Ivan Tomica
1.3k●27●33●52

just check if 24 is right answer ;)

(Aug 12 '11 at 16:23) Ivan Tomica

But 'In 10 years' would mean to add 10, and '7 years ago' would mean subtraction, correct?

(Aug 12 '11 at 16:25) wrileys

yes , put it this way. if he have 24 before 7 years he had 17 , and for 10 years he will have 34 and that is double than he had 7 years ago (17)

(Aug 12 '11 at 16:27) Ivan Tomica

You are correct!

2(24 - 7 = 17) = (24 + 10)

x = 24

(Aug 12 '11 at 16:28) Mattophobia ♦♦

;) i know i am. in highschool (that was last year)i was sooooo bad in math, and now, i rock ;)

(Aug 12 '11 at 16:30) Ivan Tomica

Same! High-five

(Aug 12 '11 at 16:38) Mattophobia ♦♦

High Five :) You just need to practice. and you should accept my answer ;)

(Aug 12 '11 at 16:41) Ivan Tomica

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-1

x+10=2x-7 So x, bob, must be 17

answered Aug 12 '11 at 16:16

wrileys
340●4●6●17

edited Aug 12 '11 at 16:17

Close, but the question states that he will be "twice as old as he was 7 years ago." Therefore, the equation looks like:

x+10 = 2(x-7)

Distributing: x+10 = 2x-14

Simplify: 24 = 2x - x = x

(Aug 12 '11 at 16:39) eddieringle

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