A person throws two dice, one the common cube and the other a regular tetrahedron, the number on the lowest face being taken in the case of the tetrahedron. What is the chance that the sum of the number thrown is not less five?
None of these
Total numbers of ways , because in a tetrahedron there are four faces and in a cube there are six faces. To obtain the favourablenumber of ways, we find the sum of coefficient of powers of x less than 5 in the expansion.
and subtract this sum from 24.
Now the coefficient of x4 in (i) = 3
The coefficient of x3 in (i) = 2
The coefficient of x2 in (i) = 1
Sum of the coefficients = 6
m = Favourable number of ways = 24 – 6 = 18
There are four machines and it is know that exactly two of them are faulty. They are tested, one by one, in a random order till both the faulty machines are indentified. Then the probability that only two tests are needed is
A person draws a card from a pack of playing card, replaces it and shuffles the pack. He continues doing this until he shows a spade. The chance that he will fail the first two times is
The probability that in toss of two dice we obtain the sum 7 and 11 is
Two cards are draw at random from a pack of 52 cards. The probability of these two being aces is
An urn contains 3 white and 5 black balls. One ball is draw. What is the probability that it is black?
Forms a pack of 52 cards, four cards are drawn. Find the chance that they will be the four honours of the same suit.
If a coin tossed 15 times, what is the probability of getting head as many times in the first ten throws as in the last five?
The card are draw successively with replacement from a well shuffled deck of 52 cards. The probability of drawing two aces is
The chance of throwing an ace is the first only of two successive thrown with an ordinary die is