Malik's recipe for 4 servings of a certain dish requires 3/2

This topic has expert replies
Moderator
Posts: 426
Joined: Tue Aug 22, 2017 8:48 pm
Followed by:1 members
Malik's recipe for 4 servings of a certain dish requires 3/2 cups of pasta. According to this recipe, what is the number of cups of pasta that Malik will use the next time he prepares this dish?

(1) The next time he prepares this dish, Malik will make half as many servings as he did the last time he prepared the dish.
(2) Malik used 6 cups of pasta the last time he prepared this dish.

What's the best way to determine which statement is sufficient? Any experts can help please?

User avatar
GMAT Instructor
Posts: 15539
Joined: Tue May 25, 2010 12:04 pm
Location: New York, NY
Thanked: 13060 times
Followed by:1906 members
GMAT Score:790

pasta

by GMATGuruNY » Fri Feb 23, 2018 5:00 am
ardz24 wrote:Malik's recipe for 4 servings of a certain dish requires 3/2 cups of pasta. According to this recipe, what is the number of cups of pasta that Malik will use the next time he prepares this dish?

(1) The next time he prepares this dish, Malik will make half as many servings as he did the last time he prepared the dish.
(2) Malik used 6 cups of pasta the last time he prepared this dish.
3/2 cups of pasta are required for every 4 servings.

Statement 1:
Case 1: 8 servings made last time, 4 servings to be made next time
Since 3/2 cups are required for every 4 servings, the number of cups required for the 4 cups to be made next time = 3/2.
Case 2: 16 servings made last time, 8 servings to be made next time
Since 3/2 cups are required for every 4 servings, the number of cups required for the 8 cups to be made next time = 2(3/2) = 3.
Since the number of cups can be different values, INSUFFICIENT.

Statement 2:
Since the number of servings to be made next time is unknown, INSUFFICIENT.

Statements combined:
Since Malik used 6 cups of pasta last time -- and he will make 1/2 as many servings next time -- he will use 1/2 as much pasta next time, for a total of 3 cups.
SUFFICIENT.

The correct answer is C.
Private tutor exclusively for the GMAT and GRE, with over 20 years of experience.
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.

As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.

For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
Student Review #2
Student Review #3

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 16207
Joined: Mon Dec 08, 2008 6:26 pm
Location: Vancouver, BC
Thanked: 5254 times
Followed by:1268 members
GMAT Score:770

by Brent@GMATPrepNow » Fri Feb 23, 2018 7:56 am
Target question: How many cups of pasta will Malik use the next time he prepares this dish?

Given: 4 servings of a certain dish requires 1 1/2 cups of pasta.
So, if we can determine the NUMBER OF DISH SERVINGS Malik prepares, we can determine how much past is required.

Statement 1: The next time he prepare this dish, Malik will make half as many servings as he did the last time he prepared the dish
We have no idea how many servings Malik made last time. So, we cannot determine the number of servings he'll make next time.
So, statement 1 is NOT SUFFICIENT

Statement 2: Malik used 6 cups of pasta the last time he prepared this dish
This information does not help us determine how much pasta he'll need NEXT TIME.
So, statement 2 is NOT SUFFICIENT

Statements 1 and 2 combined
Statement 2: Malik used 6 cups of pasta the last time
Statement 1: Next time, Malik will make half as many servings as he did the last time. If we makes half as many servings, Malik will need half as much pasta as he needed last time.
So, Malik will need 3 cups of pasta next time
Since we can answer the target question with certainty, the combined statements are SUFFICIENT

Answer = C

Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
Image