It is currently 23 Oct 2017, 07:29

### 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

# Each integer from 1 to 50 whose units digit is a 3 is writte

Author Message
TAGS:
Moderator
Joined: 18 Apr 2015
Posts: 2158
Followers: 30

Kudos [?]: 313 [0], given: 1278

Each integer from 1 to 50 whose units digit is a 3 is writte [#permalink]  22 May 2017, 00:53
Expert's post
00:00

Difficulty:

5% (low)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions

Each integer from 1 to 50 whose units digit is a 3 is written on a slip of paper and placed in a box. If two slips of a paper arc drawn at random without replacement, what is the probability that both the numbers picked are prime?

[Reveal] Spoiler: OA
\frac{3}{5}

_________________
GRE Instructor
Joined: 10 Apr 2015
Posts: 638
Followers: 29

Kudos [?]: 450 [1] , given: 3

Re: Each integer from 1 to 50 whose units digit is a 3 is writte [#permalink]  05 Aug 2017, 13:33
1
KUDOS
Expert's post
Carcass wrote:

Each integer from 1 to 50 whose units digit is a 3 is written on a slip of paper and placed in a box. If two slips of a paper arc drawn at random without replacement, what is the probability that both the numbers picked are prime?

[Reveal] Spoiler: OA
\frac{3}{5}

Each integer from 1 to 50 whose units digit is a 3 is written on a slip of paper and placed in a box.
So, the numbers in the box are: 3, 13, 23, 33, and 43 (5 numbers)
Among those 5 numbers, the primes are: 3, 13, 23, and 43 (4 numbers)

P(both are prime) = P(1st number is prime AND 2nd number is prime)
= P(1st number is prime) x P(2nd number is prime)
= 4/5 x 3/4
= 3/5

RELATED VIDEO

_________________

Brent Hanneson – Founder of greenlighttestprep.com

Check out the online reviews of our course

Re: Each integer from 1 to 50 whose units digit is a 3 is writte   [#permalink] 05 Aug 2017, 13:33
Display posts from previous: Sort by