Short Answer TypeA box contains 5 red balls, 4 green balls and 7 white balls. A ball is drawn at random from the box. Find the probability that the ball drawn is
(a) White (b) neither red nor white
(i) white ball or a green ball.
(ii) neither a green ball not a red ball.
Cards marked with the numbers 2 to 101 are placed in a box and mixed throughly. One card is drawn from this box. Find the probability that the number on the cards is
(i) an even number
(ii) a number less than 14.
(iii) a number which is a perfect square.
(iv) a prime n umber less than 20.
(i) Total no. of cards = 100
i.e., n( S)= 100
(ii) Let A be the favourable outcomes of getting an even number, then
A = {2,4,6,8,10........100}
⇒ n( A) = 50
Therefore,
(ii) Let B be the favourable outcomes of getting a number less than 14, then
B = {2,3,4,5,6...........13}
⇒ n(B) = 12
Therefore,
(iii) Let C be the favourable outcomes of getting a number which is a perfect square, then
C = {4,9,16,25,36,49,64,81,100}
⇒ n(C) = 9 Therefore,
(iv) Let D be the favourable outcomes of getting a prime number less than 20, then
D = {2,3,5,7,11,13,17,19}
⇒ n(D) = 8
Therefore,
18 Cards, numbered 1, 2, 3, ..., 18 are put in a box and mixed throughly. A card is drawn at random from the box. Find the probability that the Card drawn bears
(i) an even number
(ii) a number divisible by 2 or 3
12 cards, numbered 1, 2,3......., 12 are put in a box and mixed throughly. A card is drawn at random from the box. Find the probability that the card drawn bears
(i) an even number
(ii) a number divisible by 2 or 3.
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