The probability that an event will fail to happen is $0.05$. The probability that the event will take place on $4$ consecutive occasions is
$0.00000625$
$0.18543125$
$0.00001875$
$0.81450625$
A number is chosen from first $100$ natural numbers. The probability that the number is even or divisible by $5$, is
Two cards are drawn from a pack of $52$ cards. What is the probability that one of them is a queen and the other is an ace
In each of the following experiments specify appropriate sample space A person is noting down the number of accidents along a busy highway during a year.
Three letters are to be sent to different persons and addresses on the three envelopes are also written. Without looking at the addresses, the probability that the letters go into the right envelope is equal to
In order to get at least once a head with probability $ \ge 0.9,$ the number of times a coin needs to be tossed is