GMAT Question of the Day - Daily to your Mailbox; hard ones only

 It is currently 09 Dec 2019, 18:39

### GMAT Club Daily Prep

#### Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

Author Message
TAGS:

### Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 59622

### Show Tags

25 Apr 2019, 03:56
00:00

Difficulty:

5% (low)

Question Stats:

94% (01:24) correct 6% (02:36) wrong based on 32 sessions

### HideShow timer Statistics

Seven cookies of radius 1 inch are cut from a circle of cookie dough, as shown. Neighboring cookies are tangent, and all except the center cookie are tangent to the edge of the dough. The leftover scrap is reshaped to form another cookie of the same thickness. What is the radius in inches of the scrap cookie?

(A) $$\sqrt{2}$$
(B) 1.5
(C) $$\sqrt{\pi}$$
(D) $$\sqrt{2\pi}$$
(E) $$\pi$$

Attachment:

cca00f7535d16d5f82c2832dbebe7bf865368fed.png [ 24.84 KiB | Viewed 414 times ]

_________________
Intern
Joined: 24 Apr 2019
Posts: 19

### Show Tags

25 Apr 2019, 04:27
Area of outer circle=$$pi*3^2=9pi$$
Area of 7 cookies=$$7*pi*1^2=7pi$$

Area of left over=$$2pi$$
Radius=$$\sqrt{2}$$
IMo, Option A.
Senior Manager
Joined: 13 Jan 2018
Posts: 341
Location: India
Concentration: Operations, General Management
GMAT 1: 580 Q47 V23
GMAT 2: 640 Q49 V27
GPA: 4
WE: Consulting (Consulting)

### Show Tags

25 Apr 2019, 04:42
Each cookie area is $$\pi$$

The larger circle area is $$9\pi$$ (radius of the larger circle is 3)

Area of 7 cookies is $$7\pi$$

Scrap area is $$9\pi - 7\pi$$

$$2\pi$$

$$\pi*r^2 = 2\pi$$

$$r = \sqrt{2}$$

OPTION: A
Manager
Joined: 10 Sep 2019
Posts: 53
Location: India
Concentration: Social Entrepreneurship, Healthcare
GPA: 2.6
WE: Project Management (Non-Profit and Government)

### Show Tags

21 Nov 2019, 23:27
The radius of the entire cookie dough is 3 in. => Area of the entire dough is (pie)(r^2)

Subtracting, we get left over area as 2*(pie) = (pie)*(r^2)

=> r = root2

~ I'm not used to the using math in text ~
Display posts from previous: Sort by