SAT question help, lol

[iFargle]

Amanda travels to work from home in 60 minutes. If, on her way home, she increases her average speed by 20% and she travels by the exact same route, how many minutes will it take her to get home?

HALP

The book says the answer is 60, but I get 48. I'M CONFUSED

 

[wafflehammer]

wouldn't that depend on at what point she increased her speed? i mean..if she increased it the last 2 miles vs increased during the first 2 miles wouldn't it be different?

 

[iFargle]

I think we have to assume she's going a constant 20% faster the entire trip.

 

[wafflehammer]

uhmmmm...yea then 48 is what i would say? 20% of 60 is 12...so cut the time by 12....60-12=48?

 

[iFargle]

That's what I thought I'm guessing the book is wrong.. It's been wrong on three answers so far... I'm going to get a new book, haha

 

[wafflehammer]

yea lol..if the book is wrong i surely wouldn't want to study from it especially something as important as that

 

[iFargle]

Ha yeah. I'll just borrow one from my friend. She's got a different book and got a 2330.. But she studied for 8 months and I'll have like a week to

 

[wafflehammer]

meh i'm not a fan of studying for those kinda things..it's suppose to be what you know..not what you can cram in before it :| lol

 

[Burn]

wait, so it takes her 60minutes at first... then she goes faster... and takes her the same amount of time.

umm the books wrong...

edit: i get 50.

how i did it:
for now lets assume its 60m to her work and she goes 1 m/min. if we divide those two numbers to get time, we get 60 min.

if we take those same numbers, add 20% to the rate 1m/min to get 1.2m/min and divide 60m by that rate, = 50 min

Ha yeah. I'll just borrow one from my friend. She's got a different book and got a 2330.. But she studied for 8 months and I'll have like a week to

DUDE! thats 70 points away from getting a perfect... GEEZ