An integar is chosen at random and squared. Find the probability that the unit digit of the square is 1 or 5.

An integer is chosen at random and squared. Find the probability that the last digit of the square is 1 or 5.

Two integers are chosen at random and multiplied. Find the probability that the product is an even integer.

There are 20 boys and 15 girls in a class of 35 students . A student is chosen at random . Find the probability that the chosen student is a (i) boy (ii) girl .

If out of 20 consecutive whole numbers two are chosen at random, then find the probability that their sum is odd.

If four whole numbers taken art random are multiplied together, then find the probability that the last digit in the product is 1,3,7, or 9.

A bag contains 50 bolts and 150 nuts. Half of the bolts and half of the nuts are rusted. If an item is chosen at random, find the probability that it is rusted or that it is a bolt.

There are two identical boxes containing respectively 5 white and 3 red balls, 4 white and 6 red balls. A box is chosen at random and a ball is drawn from it (i) find the probability that the ball is white (ii) if the ball is white, what is the probability that it from the first box?