GMAT Practice Exam 1 question : Integrated Reasoning (IR)
Check GMAT Club Decision Tracker for the Latest School Decision Releases http://gmatclub.com/AppTrack

 It is currently 23 Jan 2017, 16:56

### 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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# GMAT Practice Exam 1 question

Author Message
Intern
Joined: 24 Feb 2014
Posts: 6
Followers: 0

Kudos [?]: 3 [0], given: 1

GMAT Practice Exam 1 question [#permalink]

### Show Tags

01 Mar 2014, 04:45
Its question 5 of 12 (dont know if everyone get them in same order?) in test 1. An architect is planning to incorporate several stone spheres of diffrent sizes...and so on.

Need help how to solve it
Attachments

asaddsa.png [ 1.57 MiB | Viewed 2794 times ]

Intern
Joined: 24 Feb 2014
Posts: 6
Followers: 0

Kudos [?]: 3 [0], given: 1

Re: GMAT Practice Exam 1 question [#permalink]

### Show Tags

01 Mar 2014, 05:11
1
This post was
BOOKMARKED
If you dont mind I have another question in the IR section. In the practise test I didnt have enough time so I just guessed on this one.

But now when Im reviewing the test I dont understand how to read the tabel on the first question.
Attachments

Voters.png [ 1.58 MiB | Viewed 2787 times ]

Intern
Joined: 24 Feb 2014
Posts: 6
Followers: 0

Kudos [?]: 3 [0], given: 1

Re: GMAT Practice Exam 1 question [#permalink]

### Show Tags

01 Mar 2014, 05:23
Im new to this forum and I cant find any topic on just questions about GMAT Practice Exam 1 or 2. Please if their is tell me. I have alot of more question in the quant section...
Intern
Joined: 19 May 2014
Posts: 31
Followers: 0

Kudos [?]: 15 [2] , given: 9

Re: GMAT Practice Exam 1 question [#permalink]

### Show Tags

21 May 2014, 07:35
2
KUDOS
1
This post was
BOOKMARKED
Hi FBSK

Since this question talks about circumference and Surface Area of a sphere, let's first derive the relationship between the two.

Circumference of a Sphere, $$C = 2 pie R$$, where R is the radius of the sphere.
So,$$R=\frac{C}{2 pie}$$

Surface Area of a Sphere, $$S = 4 pie R^2$$

Substituting for the value of R,

$$S= 4 pie\frac{C^2}{(2 pie)^2}$$
So, $$S= \frac{C^2}{pie}$$

This is the result that we will use to solve this question.

For Sphere 1,
C= 5.5 m
So, $$S = \frac{(5.5)^2}{pie}$$
Put $$pie =\frac{22}{7}$$

So,$$S = \frac{55*55*7}{10*10*22}$$

$$S = \frac{77}{8}$$sq. m

So, Cost of painting the surface area of Sphere 1 = $$92*\frac{77}{8}$$
=$$23*\frac{77}{2}$$

Now, here I want you to be smart. Look at the values in the five options. They are all quite far apart from each other. This means, that you don't need to find the exact value, true to the first or the second place of decimal. You only need a ballpark estimate of the cost.

So, to quickly do this rough estimate, let's replace 23 with 22. You can appreciate how easy our calculation now becomes!

$$11*77 = 847$$

The option closest to this is 900. So, our answer for the first sphere will be 900.

Now, coming to the second sphere:

We'll again use the formula $$S= \frac{C^2}{pie}$$

Here, $$S = \frac{(7.85)^2}{pie}$$

Seems like a complex calculation, huh?

Let's just hold on the calculation for a minute and put in the formula for costs.

Cost of painting Sphere 2 = $$92* \frac{(7.85)^2}{pie}$$
= $$92*7.85*7.85*\frac{7}{22}$$

Now we'll simplify these decimals to get an approximate value of the cost:

Cost = $$4*8*8*7$$ (because $$\frac{92}{22}$$ is approximately equal to 4)
= 1792

The closest option to this is 1800. So, we'll choose it as our answer.

Hope this helped!
_________________

Please press Kudos if you were helped by my post!

Intern
Joined: 11 Sep 2014
Posts: 9
Followers: 0

Kudos [?]: 2 [0], given: 5

Re: GMAT Practice Exam 1 question [#permalink]

### Show Tags

28 Sep 2014, 04:47
FBSK wrote:
If you dont mind I have another question in the IR section. In the practise test I didnt have enough time so I just guessed on this one.

But now when Im reviewing the test I dont understand how to read the tabel on the first question.

The points on the graph represent previous votes and the location of those points on the graph represents the probability that the previous votes will stay the same in the next voting. Therefore, Delta has 80% probability that previous votes "for" will stay the same, which is the highest out of all.
_________________

What we think, we become

Re: GMAT Practice Exam 1 question   [#permalink] 28 Sep 2014, 04:47
Similar topics Replies Last post
Similar
Topics:
IR Practice Exam 4 Question 3 3 20 Feb 2015, 09:53
2 Difficult IR Question from Exam Pack 1 3 04 Nov 2013, 07:42
3 IR Practice Questions 1 11 Nov 2012, 18:16
IR Practice question 1 23 Jul 2012, 07:09
7 practice TA question 4 27 Jun 2012, 10:18
Display posts from previous: Sort by