Test: Probability Theory - 2 - SSC CGL

Here, S = {1, 2, 3, 4, ...., 19, 20}
Let E = event of getting a multiple of 3 or 5
= {3, 6 , 9, 12, 15, 18, 5, 10, 20}

Total number of balls
= (8 + 7 + 6)
= 21
Let E = event that the ball drawn is neither red nor green
= event that the ball drawn is blue
∴n(E)=7

Getting at most Two heads means 0 to 2 but not more than 2
Here S = {TTT, TTH, THT, HTT, THH, HTH, HHT, HHH}
Let E = event of getting at most two heads
Then E = {TTT, TTH, THT, HTT, THH, HTH, HHT}

Let S be the sample space and E be the event of selecting 1 girl and 2 boys
Then, n(S) = Number ways of selecting 3 students out of 25

Let S be the sample space


Let E = event of getting 2 kings out of 4

Let S be the sample space
Then, n(S) = number of ways of drawing 3 balls out of 15

Let E = event of getting all the 3 red balls

Clearly, there are 52 cards, out of which there are 12 face cards.
∴P(getting a face card)

Here, S = {1, 2, 3, 4,........, 19, 20}
Let E = even of getting a multiple of 3 = {3, 6, 9, 12, 15, 18}

Total number of marbles = (6 + 4 + 2 + 3) = 15
Let E be the event of drawing 4 marbles such that none is blue.
Then, n(E) = number of ways of drawing 4 marbles out of 11 non-blue.

Hence, n(S) = 52
Let E = event of getting a queen of club or a king of heart.
Then, n(E) = 2