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Problem on probability

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by singhpreet1 » Thu Jul 22, 2010 10:17 pm
Pinku wrote:Given few numbers like 2, 5, 6, 7, 9. Find the number of ways of arranging a five digit even number from the given numbers?
for the number to be even, only 2 and 6 are even in the above given list, so the units place must be always 2 or 6. therefore the units place can be arranged in 2! or 2 ways
the rest of the 3 numbers can be rearranged to form different 5 digit numbers in 3!

then total number of ways to arrange is 3!*2!= 12 ways

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by outreach » Thu Jul 22, 2010 11:31 pm
3!*2!
Pinku wrote:Given few numbers like 2, 5, 6, 7, 9. Find the number of ways of arranging a five digit even number from the given numbers?
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by ipinnacle » Fri Jul 23, 2010 7:14 am
I Don't agree with the answer 3!*2!

The question does not mention that the numbers can not be repeated.
So considering repetition,
the answer will be 5*5*5*5*2=1250
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by paridhi » Fri Jul 23, 2010 9:34 pm
Since number needs to be even, only 2 and 6 can be used in the units place.

Suppose, 2 is in the units place, then number of such 5 digit numbers will be 4!

Suppose, 6 is in the units place, then number of such 5 digit numbers will be 4!

Thus answer should be 2*4! = 48

what is the OA?
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