137 simultaneous equation

Expert replies

phoenix9801: Master | Next Rank: 500 Posts; Posts: 190; Joined: Thu Jan 14, 2010 8:29 pm; Thanked: 2 times

by phoenix9801 » Sat Jul 10, 2010 11:14 pm

Hi, can someone please help to explain by step-by-step instructions (in detail) in the most simplest way and clear to understand. Would Greatly appreciate it.

At a bakery, all donuts are priced equally and all bagels are priced equally. What is the total price of 5 donuts and 3 bagels at the bakery?

(1) At the bakery, the total price of 10 donuts and 6 bagels is $12.90

(2) At the bakery, the price of a fount is $0.15 less than the price of a bagel.

Last edited by phoenix9801 on Mon Jul 12, 2010 1:48 pm, edited 1 time in total.

Like this post

Source: Beat The GMAT — Data Sufficiency | Sat Jul 10, 2010 11:14 pm

albatross86: Master | Next Rank: 500 Posts; Posts: 392; Joined: Sun May 16, 2010 2:42 amFollowed by: 10 members; Location: Bangalore, India; Thanked: 116 times; GMAT Score:770

by albatross86 » Sat Jul 10, 2010 11:25 pm

Let price of each donut be D and of each bagel be B.
What is 5D + 3B?

1. 10D + 6B = 12.90$

This is an important takeaway for DS. Whenever you have an equation like this which is actually just a multiple of our required solution, it is sufficient, and though we have two variables, we can isolate our target value.

i.e. Divide the above equation by 2:

5D + 3B = 6.45@ ...Ans

SUFFICIENT

2. D = B - 0.15$

This won't be sufficient to find each value or to obtain 5D + 3B

INSUFFICIENT

Pick A.

~Abhay

Believe those who are seeking the truth. Doubt those who find it. -- Andre Gide

Like this post

phoenix9801: Master | Next Rank: 500 Posts; Posts: 190; Joined: Thu Jan 14, 2010 8:29 pm; Thanked: 2 times

by phoenix9801 » Mon Jul 12, 2010 1:47 pm

albatross86 wrote:Let price of each donut be D and of each bagel be B.
What is 5D + 3B?

1. 10D + 6B = 12.90$

This is an important takeaway for DS. Whenever you have an equation like this which is actually just a multiple of our required solution, it is sufficient, and though we have two variables, we can isolate our target value.

i.e. Divide the above equation by 2:

5D + 3B = 6.45@ ...Ans

SUFFICIENT

2. D = B - 0.15$

This won't be sufficient to find each value or to obtain 5D + 3B

INSUFFICIENT

Pick A.

Thanks for the help....

I would know if you can further explain what you mean by this " Whenever you have an equation like this which is actually just a multiple of our required solution, it is sufficient"?????????????

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