BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

3-digit numerals

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
User avatar
Legendary Member
Posts: 1132
Joined: Mon Jul 20, 2009 3:38 am
Location: India
Thanked: 64 times
Followed by:6 members
GMAT Score:760

3-digit numerals

by harsh.champ » Tue Feb 09, 2010 4:55 am
How many 3-digit numerals begin with a digit that represents a prime and end with a digit that represents a prime number?

(A)16
(B)80
(C)160
(D)180
(E)240

The OA is C.
It takes time and effort to explain, so if my comment helped you please press Thanks button :)



Just because something is hard doesn't mean you shouldn't try,it means you should just try harder.

"Keep Walking" - Johnny Walker :P
Top
Source: — Problem Solving |
User avatar
Legendary Member
Posts: 1022
Joined: Mon Jul 20, 2009 11:49 pm
Location: Gandhinagar
Thanked: 41 times
Followed by:2 members

by shashank.ism » Tue Feb 09, 2010 4:58 am
harsh.champ wrote:How many 3-digit numerals begin with a digit that represents a prime and end with a digit that represents a prime number?

(A)16
(B)80
(C)160
(D)180
(E)240

The OA is C.
The first digit can be 2, 3, 5, or 7 (4 choices) The second digit can be 0, 1, 2, 3, 4, 5, 6, 7, 8, or 9 (10 choices)
The third digit can be 2, 3, 5, or 7 (4 choices) 4 * 4 * 10 = 160
Ans is C
My Websites:
www.mba.webmaggu.com - India's social Network for MBA Aspirants

www.deal.webmaggu.com -India's online discount, coupon, free stuff informer.

www.dictionary.webmaggu.com - A compact free online dictionary with images.

Nothing is Impossible, even Impossible says I'm possible.
Top
User avatar
Legendary Member
Posts: 1275
Joined: Thu Sep 21, 2006 11:13 pm
Location: Arabian Sea
Thanked: 125 times
Followed by:2 members

by ajith » Tue Feb 09, 2010 6:55 am
harsh.champ wrote:How many 3-digit numerals begin with a digit that represents a prime and end with a digit that represents a prime number?

(A)16
(B)80
(C)160
(D)180
(E)240

The OA is C.
first digit can be 2,3,5,7 =4 possibilities
Last digit can be 2,3,5,7 =4 possibilities
Middle digit can be 0-9 =10 possibilities

total = 4*4*10 = 160
Always borrow money from a pessimist, he doesn't expect to be paid back.
Top
Post new topic Post Reply
• Page 1 of 1