GMAT Question of the Day: Daily via email | Daily via Instagram New to GMAT Club? Watch this Video

 It is currently 06 Jul 2020, 20:03

### 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

# The probability of Tom rolling a strike while bowling is 40% on any

Author Message
TAGS:

### Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 65014
The probability of Tom rolling a strike while bowling is 40% on any  [#permalink]

### Show Tags

21 May 2019, 22:41
00:00

Difficulty:

65% (hard)

Question Stats:

54% (02:17) correct 46% (02:30) wrong based on 48 sessions

### HideShow timer Statistics

The probability of Tom rolling a strike while bowling is 40% on any given frame. If Tom rolls 4 frames in a row, which of the following statements are true?

I. The probability of Tom rolling a strike on all 4 frames is greater than 3%.

II. The probability of Tom rolling no strikes in 4 frames is less than 10%.

III. Tom is equally likely to roll exactly 1 strike as to roll exactly 2 strikes in those 4 frames.

A. I only
B. II only
C. III only
D. I and III only
E. I, II and III

_________________
Director
Status: Manager
Joined: 27 Oct 2018
Posts: 800
Location: Egypt
GPA: 3.67
WE: Pharmaceuticals (Health Care)
The probability of Tom rolling a strike while bowling is 40% on any  [#permalink]

### Show Tags

22 May 2019, 01:23
1
1
I. The probability of Tom rolling a strike on all 4 frames is greater than 3%?
probability of 4 strikes = $$0.4^4 = 0.0256 < 0.03$$ --> false

II. The probability of Tom rolling no strikes in 4 frames is less than 10%?
probability of no strikes = $$0.6^4 = 0.1296 > 0.1$$ --> false

so A,B,D,E are eliminated & C is the answer

to confirm, we can check statement 3:

III. Tom is equally likely to roll exactly 1 strike as to roll exactly 2 strikes in those 4 frames? --> true
probability of exactly 1 = $$\frac{2}{5}*\frac{3}{5}*\frac{3}{5}*\frac{3}{5} * \frac{4!}{3!} = \frac{2*3*3*3*4}{5*5*5*5}$$
probability of exactly 2 = $$\frac{2}{5}*\frac{2}{5}*\frac{3}{5}*\frac{3}{5} * \frac{4!}{2!*2!} = \frac{2*3*3*3*4}{5*5*5*5}$$
Non-Human User
Joined: 09 Sep 2013
Posts: 15382
Re: The probability of Tom rolling a strike while bowling is 40% on any  [#permalink]

### Show Tags

29 May 2020, 04:27
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________
Re: The probability of Tom rolling a strike while bowling is 40% on any   [#permalink] 29 May 2020, 04:27