MCA Entrance Previous Year Question Bank

Let the quadratic equation $a{x}^2+bx+c=0$ where a, b,c are obtained by rollinq the dice thrice. What is the probability that the equation has equal roots?

A and B are two students. Their chances of solvinq a problem correctly are $\frac{1}{3}$ and $\frac{1}{4}$, respectively. If the orobability of their making a common error is $\frac{1}{20}$ and they obtain the same answer, then the probability of their answer to be correct is:

Three persons A, B and C fire at a target in turn, starting with A. Their probabilities of hitting the target are 0.4, 0.3 and 0.2 respectively. The probability of two hits is:

The probability that at least one of the events $A$ and $B$ occurs is $0.6$. If $A$ and $B$ occur simultaneously with probability $0.2$, then $P(\bar{A})+P(\bar{B})$ is:

Three numbers are chosen from 1 to 20. Find the probability that they are not consecutive.

A pair of fair dice is thrown independently 3 times. The probability of getting a score of exactly 9 twice is

A card is drawn from a pack of 52 cards. A gambler bets that it is a spade or an ace. What are odds against his winning this bet?