[njoy]

Originally Posted by medulla

In how many ways can the letter of the word "daughter" be arranged such that no vowels are together?

answer this question with explanation

total number f permutions possible= 8!

Total number f permutations wth all the vowels always togther= 6!*3!

Thus total number f permutations when vowels are nt together= 8! - 6!.3!= 36000.

[de_profundis]

Originally Posted by njoy

total number f permutions possible= 8!

Total number f permutations wth all the vowels always togther= 6!*3!

Thus total number f permutations when vowels are nt together= 8! - 6!.3!= 36000.

@njoy:

Actually - thats not correct. There are three vowels in all. So you need to deduct the cases where two vowels also come together to get the cases where no vowels are together. I myself am too lazy right now to do it though - but thats how you arrive at the right answer.

- de profundis

[m10009]

In a company, there are 365 people working.what is the probability that no one has birthday on the same day..considering the year NOT a leap year

[de_profundis]

Originally Posted by m10009

In a company, there are 365 people working.what is the probability that no one has birthday on the same day..considering the year NOT a leap year

Assuming both people and dates of birth are distinguishable, 365 people can have their birthdays spread across the year in 365^365 ways.

Of these, the number of ways the birthdays can be arranged such that exactly one person's birthday falls on a day is 365!

So the probability of the event happening is
= 365!/(365^365)
= 364!/(365^364)

- de profundis

[medulla]

hi people....

Okk.. Here comes one more interesting sum..

Two cards are drawn from a pack of well - shuffled cards. Find the probability that one is spade and other is king


:grab:

[de_profundis]

Originally Posted by medulla

hi people....

Okk.. Here comes one more interesting sum..

Two cards are drawn from a pack of well - shuffled cards. Find the probability that one is spade and other is king


:grab:

I have an answer - not too sure though.

There are two cases - the first card can be a non-king spade or the first card can be a king spade. The non-king spade can be drawn in 12 ways and the king spade can be drawn in 1 way.

So, we have:
Probability = Probability of drawing a non-king spade and any of the four kings OR Probability of drawing a king spade and any of the three kings.

Probability = (12/52)*(4/51) + (1/52)*(3/51)
= (48/2652) + (3/2652)
= 51/2652

We need to multiply the answer by 2 since the order does not matter.

Probability = 102/2652

I think this is the answer but it looks suspiciously low.??: Any other answers?

- de profundis

[krsh.vik]

Originally Posted by medulla

hi people....
Two cards are drawn from a pack of well - shuffled cards. Find the probability that one is spade and other is king

total 52c2
1*15+12*3/26*51 = 1/26

[sanjayr84]

Guys..I have a question:
"There are exactly 26 keys on a key-board (for letters A-Z). I need to type "THANKYOU", but without looking at the keyboard and the screen. I press 8 keys at random. What is the probability that the word entered by me is spelt correctly."

Awaiting answers..
Cheers

[de_profundis]

Originally Posted by sanjayr84

Guys..I have a question:
"There are exactly 26 keys on a key-board (for letters A-Z). I need to type "THANKYOU", but without looking at the keyboard and the screen. I press 8 keys at random. What is the probability that the word entered by me is spelt correctly."

Awaiting answers..
Cheers

Out of 26 keys, 8 keys can be typed in 26^8 ways (with repetition). The correct word can be typed in one way. So the probability is

Probability = 1/( 26^8 )

- de profundis

[vyomb]

Two cards are drawn from a pack of well - shuffled cards. Find the probability that one is spade and other is king

hey medulla wats the ans for the ques..