Solution: Show
(ii) If a king is drawn first and put aside, what is the probability that the second card picked up is the(a) ace?Solution:
(b) king?Solution:
Question 20. A bag contains 3 red balls and 5 black balls. A ball is drawn at random from the bag. What is the probability that the ball drawn is:(i) RedSolution:
(ii) BackSolution:
Question 21. A game of chance consists of spinning an arrow which is equally likely to come to rest pointing to one of the number, 1, 2, 3, …., 12 as shown in figure. What is the probability that it will point to:(i) 10?Solution:
(ii) an odd number?Solution:
(iii) a number which is multiple of 3?Solution:
(iv) an even number?Solution:
Question 22. In a class, there are 18 girls and 16 boys. The class teacher wants to choose one pupil for class monitor. What she does, she writes the name of each pupil on a card and puts them into a basket and mixes thoroughly. A child is asked to pick one card from the basket. What is the probability that the name written on the card is:(i) The name of a girlSolution:
(ii) The name of a boy?Solution:
Question 23. Why is tossing a coin considered to be a fair way of deciding which team should choose ends in a game of cricket?Solution:
Question 24. What is the probability that a number selected at random from the number 1, 2, 2, 3, 3, 3, 4, 4, 4, 4 will be their average?Solution:
Question 25. There are 30 cards, of same size, in a bag on which numbers 1 to 30 are written. One card is taken out of the bag at random. Find the probability that the number on the selected card is not divisible by 3.Solution:
Question 26. A bag contains 5 red, 8 white and 7 black balls. A ball is drawn at random from the bag. Find the probability that the drawn ball isSolution:
Question 27. Find the probability that a number selected from the number 1 to 25 is not a prime number when each of the given numbers is equally likely to be selected.Solution:
Question 28. A bag contains 8 red, 6 white and 4 black balls. A ball is drawn at random from the bag. Find the probability that the drawn ball is(i) Red or whiteSolution:
(ii) Not blackSolution:
(iii) Neither white nor blackSolution:
Question 29. Find the probability that a number selected at random from the numbers 1, 2, 3…. 35 is a:(i) Prime numberSolution:
(ii) Multiple of 7Solution:
(iii) Multiple of 3 or 5Solution:
Question 30. From a pack of 52 playing cards Jacks, queens, kings and aces of red color are removed. From the remaining, a card is drawn at random. Find the probability that the card drawn is(i) a black queenSolution:
(ii) a red cardSolution:
(iii) a black jackSolution:
(iv) a picture card (Jacks, queens and kings are picture cards)Solution:
Question 31. A bag contains lemon-flavoured candies only. Malini takes out one candy without looking into the bag. What is the probability that she takes out:(i) an orange-flavoured candySolution:
(ii) a lemon flavored candySolution:
Question 32. It is given that in a group of 3 students, the probability of 2 students not having the same birthday is 0.992. What is the probability that the 2 students have the same birthday?Solution:
Question 33. A bag contains 3 red balls and 5 black balls. A ball is drawn at random from the bag. What is the probability that the ball drawn is(i) redSolution:
(ii) not redSolution:
Question 34. A box contains 5 red marbles, 8 white marbles and 4 green marbles. One marble is taken out of the box at random. What is the probability that the marble taken out will be(i) redSolution:
(ii) not green
Question 35. A lot consists of 144 ball pens of which 20 are defective and others good. Nuri will buy a pen if it is good, but will not buy if it is defective. The shopkeeper draws one pen at random and gives it to her. What is the probability that(i) She will buy itSolution:
(ii) She will not buy itSolution:
Question 36. 12 defective pens are accidentally mixed with 132 good ones. It is not possible to just look at pen and tell whether it is defective. One pen is taken out at random from this lot. Determine the probability that the pen taken out is good one.Solution:
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