- A bag contains 8 green balls and 12 blue balls. If a ball is drawn randomly, then find the probability of getting either green ball or blue ball.
232/52/31Option E

required = (8C1) + (12C1) = 20

total = (20C1) = 20

probability = 20/20 = 1 - If two cards are drawn randomly from a pack of 52 cards. Then what is the probability of both cards are red cards ?
28/9123/10825/102817Option C

required = (26C2) = 13 * 25

Total = (52C2) = 26 * 51

probability = (13 * 25)/(26 * 51) = 25/102 - How ,any 4-digit numbers can be formed from the digits 6, 2, 5, 7, 3, which are divisible by 5 and none of the digits is repeated ?
140220282496Option D

A number to be divisible by 5, unit digit must be 0 or 5.

So, in 4-digit numbers unit place is required to be filled by digit 5 and rest three places of required 4-digit numbers will be filled by rest 4 digit.

numbers of ways = 4! = 4 * 3 * 2 * 1 = 24 - Out of 52 playing cards two cards is picked randomly, then what is the probability of getting that one red king and one black queen ?
2/6635/138/58514Option A

required = (2C1) * (2C1) = 4

Total = (52C2) = 26 * 51

probability = 4/(26*51) = 2/663 - A bag contains 2 red pens, 6 blue pens and 4 green pens. Find the probability of getting two same color pens from the bag ?
5/82/41/35/64Option C

required = (2C2) + (6C2) + (4C2)

= 1 + 15 + 6 = 22

total = (12C2) = 66

probability = 22/66 = 1/3 - A basket contains 3 green, 4 orange and 5 pink balls. If two balls are drawn randomly from the basket, then what the probability of selecting that both balls are of different colors ?
4/6557/688/4547/664/15Option D

possibility of both balls are different colors = ( 1 green and 1 orange) , (1 orange and 1 pink ), (1 green and 1 pink)

required = (3C1) * (4C1) + (4C1) * (5C1) + (3C1) * (5C1)

= 12 + 20 + 15 = 47

total = (12C2) = 66

probability = 47/66 - Sunil threw two dices together. What is the probability of getting that the sum of the two outcomes is 4 ?
1/81/12452Option B

Possibility to get = (2, 2), (3, 1), (1, 3)

required = 3

total = 36

probability = 3/36 = 1/12 - When three coins are tossed simultaneously, then find the probability of getting at least one tale.
7/85/81/44/152Option A

possibility = 1 tale or 2 tale or 3 tale

required = (3C1) + (3C2) + (3C3)

= 3 + 3 + 1 = 7

total = 2^3 = 8

probability = 7/8 - Four boys and 2 girl sit in a row for presenting their project paper, then what is the probability that they will sit in alternate position ?
1/62/31/81/152/5Option D

probability = 4! * 2!/6! = 1/15 - Probability of a question solved by A and B is 1/5 and 1/4 respectively, then find the probability that at least one of them will solve the questions ?
5/61/411/252/55/9Option D

possibility = 1 – probability of question not solved by anyone

probability = 1 – (1 – 1/5) * (1 – 1/4)

= 1-(4/5) * (3/4)

= 2/5