bushel of corn

Expert replies

vittalgmat: Legendary Member; Posts: 621; Joined: Wed Apr 09, 2008 7:13 pmFollowed by: 4 members; Thanked: 33 times

by vittalgmat » Mon Jan 19, 2009 9:30 am

Hi,
I searched BTG for solution to this, but could not find.
So I am posting it.

The price of a bushel of corn is currently $3.20, and the price of a peck of wheat is $5.80. The price of corn is increasing at a constant rate of 5x cents per day, while the price of wheat is decreasing at a constant rate of sqrt2*x- x cents per day. What is the approximate price when a bushel of corn costs the same amount as a peck of wheat?

(A) $4.50
(B) $5.10
(C) $5.30
(D) $5.50
(E) $5.60

Like this post

Source: Beat The GMAT — Problem Solving | Mon Jan 19, 2009 9:30 am

logitech: Legendary Member; Posts: 2134; Joined: Mon Oct 20, 2008 11:26 pmFollowed by: 25 members; Thanked: 237 times; GMAT Score:730

Re: bushel of corn

by logitech » Mon Jan 19, 2009 9:41 am

320+5x=580-(sqrt2*x- x)

5x+ sqrt2*x- x = 260

4x+1.4X=260

5.4x=260

5x is around 240 cents , or 2 dollars 40 cents

Remember we are looking for a 5x increase over 320

320+240=560

LGTCH
---------------------
"DON'T LET ANYONE STEAL YOUR DREAM!"

Like this post

vittalgmat: Legendary Member; Posts: 621; Joined: Wed Apr 09, 2008 7:13 pmFollowed by: 4 members; Thanked: 33 times

by vittalgmat » Mon Jan 19, 2009 9:50 am

Hi Logitech,
I read the problem differently. here is what I thought: Pls correct me.

corn is increasing at the rate of 5x cents/day while wheat is decreasing at the rate of sqrt(2)x -x cents/day. So in Y days the prices become equal.
So find y and then find x.
And this is where I got lost..

Thanks

Like this post

logitech: Legendary Member; Posts: 2134; Joined: Mon Oct 20, 2008 11:26 pmFollowed by: 25 members; Thanked: 237 times; GMAT Score:730

by logitech » Mon Jan 19, 2009 10:04 am

vittalgmat wrote:Hi Logitech,
I read the problem differently. here is what I thought: Pls correct me.

corn is increasing at the rate of 5x cents/day while wheat is decreasing at the rate of sqrt(2)x -x cents/day. So in Y days the prices become equal.
So find y and then find x.
And this is where I got lost..

Thanks

You are right and at the of the Yth day their prices will be equal so you can solve the both equations for the same DAY. Which means do not get lost with Y!

320+5XY = 580-Y(BLABLA)

Y(BLABLA)+5XY=260

Y(BLABLA+5X)=260

Y= 260/(BLABLA+5X)

and you get lost

LGTCH
---------------------
"DON'T LET ANYONE STEAL YOUR DREAM!"

Like this post

Post new topic Post Reply

• Page 1 of 1

GMAT Course Reviews

560 reviews

1168 reviews

431 reviews

359 reviews

147 reviews

5/5

5 Star (560 Reviews)

"Target Test Prep is the closest to the official version of the GMAT exam, about 99% accuracy in terms of the quality and quantity of information. The course has excellently created singular sets of focused lessons and tests for every possible topic that one could come across in the official GMAT exam."

"The TTP course maximizes the efficiency of the time you spend studying. It will take time and effort but I could almost guarantee that if you complete the course exactly as it is laid out you will get an amazing score. They also have a very responsive team willing to help with any questions you might have."

"TTP has two things that I think no other test prep company offers: A teaching approach that reinforces understanding and an attitude that will give you the mental preparedness needed to succeed on the test. TTP gives you a deep understanding of the concept you need to know while teaching you how to think."

Write a Review