The number of five 5-digit telephone numbers having at least one of their digits repeated is
A) 90000
B) 10000
C) 30240
D) 69760
E) None of these
Subscribe to:
Post Comments (Atom)
is intended to be a spot where any student preparing for GRE can discuss study topics,find or provide tips & works towards a top score along with other students working for the same goal.Answer"GRE WORD OF THE DAY", "GRE SENTENCE COMPLETION OF THE DAY", "GRE ANALOGY OF THE DAY", "GRE ANTONYM OF THE DAY", "GRE MATH PROBLEM OF THE DAY", "GRE ALGEBRA QUESTION OF THE DAY", "GRE GEOMETRY QUESTION OF THE DAY"& "GRE PASSAGE OF THE WEEK". To get a top score,the first step of the ladder starts from here.
GRE QUESTION ON DEMAND
Send your doubts and questions to gretimes@in.com
we will post your doubt / questions along with your name on GRE Study Forum.
we will post your doubt / questions along with your name on GRE Study Forum.
GRE Information / Downloads
Blog Archive
-
►
2009
(24)
- ► April 12 - April 19 (7)
- ► April 5 - April 12 (12)
- ► March 29 - April 5 (5)
-
►
2007
(581)
- ► July 29 - August 5 (9)
- ► July 15 - July 22 (8)
- ► July 1 - July 8 (9)
- ► June 17 - June 24 (18)
- ► June 10 - June 17 (26)
- ► June 3 - June 10 (16)
- ► May 27 - June 3 (19)
- ► May 20 - May 27 (8)
- ► May 13 - May 20 (25)
- ► May 6 - May 13 (6)
- ► April 29 - May 6 (24)
- ► April 22 - April 29 (12)
- ► April 15 - April 22 (26)
- ► April 8 - April 15 (13)
- ► April 1 - April 8 (7)
- ► March 25 - April 1 (31)
- ► March 18 - March 25 (14)
- ► March 11 - March 18 (30)
- ► March 4 - March 11 (9)
- ► February 25 - March 4 (32)
- ► January 28 - February 4 (43)
- ► January 21 - January 28 (44)
- ► January 14 - January 21 (45)
ORKUT members JOIN HERE
Posts
For More Information Contact-
gretimes@in.com
GRE is a registered trademark of the Education Testing Service (ETS).
This site and its products have neither been reviewed nor endorsed by ETS.
16 comments:
D is d ans i got
it seems to b 69760...
is it right?
it seems to b 69760...
is it right?
it seems to b 69760...
is it right?
hey... u r ryt.. the answer id 69760
It's 10^5 - 10x9x8x7x6
atul how is it 10^5?
they say repeat only 1ce?
it should be 69760
can u explain in detail. i am unable to catch it
here the logic is appllied of permutation combination 10^5 means at every digit there are 10 possibilities like there are five digit A B C D E every digit having 10 possibilities and we sustract from 10^5 are 10*9*8*7*6 because these digits having no repetation hence the result is that if we do 10^5-10*9*8*7*6 then we get the result 69760 means these are number in which atleast one digit would be repeated...........Kuldeep
Number of digits=5
Max possibilities for each digit= 10 (from 0 to 9)
Max possible numbers from 5 digits= 10x10x10x10x10=10^5.....(1)
Max Possible numbers in which there is not a single reptition=
10x9x8x7x6.................(2)
If you will subtract (2) from (1), you will get the max numbers of 5 digits which have atleast one repetion.
10^5-10x9x8x7x6=69760
Abhishek
the questions said : "The number of five 5-digit telephone numbers having at least one of their digits repeated is"..
at least one of the digits repeated means it can have more than one digit repeated...
so the anwser would be
9*10*10*10*10 = 90000
5th place can be filled with all digits except zero so 9..and the following places can be filled with any of the 10 digits..
meghna said that, first place cant b filled with zero, but telephone number can be filled with zero cause zero is correct for telephone number.
I am going for a professional to solve this critical problems.
D is correct 10^5
Why are 10,9,8,7,6 the numbers that are not repeated?
Why are 10,9,8,7,6 the numbers that are not repeated?
Why are 10,9,8,7,6 the numbers that are not repeated?
Post a Comment