CAT Exam

five different digits are given out of these digits 4 digit numbers are formed fine the no of 4 digit numbers formed which has at lest one digit repeted

Read Solution (Total 4)

Answer: 5^4 - 5p4
Reason: number of 4 digit numbers formed using 5 numbers with repetition are 5^4
and number of 4 digit numbers formed from given 5 digit numbers without repetition are 5p4.Number of numbers formed with atleast 1 digit repeated are 5^4 -5p4
12 years agoHelpfull: Yes(4) No(1)

Number of such numbers = 5^4-(5*4*3*2) = 625 - 120 = 505
12 years agoHelpfull: Yes(2) No(1)
Answer: 5^4-(5*4*3*2)=625-120=505
12 years agoHelpfull: Yes(0) No(0)
for suppose, in the 5 digits, if we have 0?? then the first digit in four digit number should not take value of 0.Then probability changes.
12 years agoHelpfull: Yes(0) No(0)

CAT Other Question

A and B have to travel from place x to place y.they have enough coins 1,5,10,25 paise.
A agrees to pay for B,only if he tells all the possible combinations of coins that can be used to pay for the ticket.

a.how many combinations are possible,if the fare is 50 paise?
b.how many combinations are possible ,if they get an discount of 10%,i.e., the fare is 45paise? A person who has a certain amount with him goes to the market. He can buy 100 oranges and 80 mangoes.He wastes 20% of the amount and buys 40 mangoes and of the balance, he purchases oranges. The no. of oranges he can purchase?