Quiz Discussion

If C(n, 7) = C(n, 5), find n

• 1]

  12

• 2]

  15

• 3]

  18

• 4]

  -1

Ten participants are participating in a competition. In how many ways can the first three prizes be won?

• 1]

  920

• 2]

  680

• 3]

  720

• 4]

  820

If A, B and C are mutually exclusive and exhaustive events of a random experiment such that P(B)=3/2​P(A) and P(C)=1/2​P(B), then P(A∪C)=

• 1]

  3/13

• 2]

  6/13

• 3]

  7/13

• 4]

  10/13

There are seven pairs of black shoes and five pairs of white shoes. They are all put into a box and shoes are drawn one at a time. To ensure that at least one pair of black shoes are taken out, what is the number of shoes required to be drawn out?

• 1]

  12

• 2]

  13

• 3]

  17

• 4]

  18

If (n + 2)! = 2550 (n!); find ’n’

• 1]

  49

• 2]

  35

• 3]

  38

• 4]

  43

If A and B are two independent events with P(A) = 3/5 and P(B) = 4/9 , then P(A' ∩ B' ) equals

• 1]

  4/15

• 2]

  8/45

• 3]

  1/3

• 4]

  2/9

One card is drawn at random from a pack of 52 cards. What is the probability that the card drawn is not a face card (Jack, Queen and King only)?

• 1]

  5/13

• 2]

  10/13

• 3]

  1/13

• 4]

  1/26

How many parallelograms will be formed if 7 parallel horizontal lines intersect 6 parallel vertical lines?

• 1]

  42

• 2]

  294

• 3]

  315

• 4]

  258

A, B, C, D and E sit on five chairs all of which are facing north. C will sit only on the leftmost chair and B will not sit anywhere to the left of A. In how many ways they can be seated?

• 1]

  10

• 2]

  18

• 3]

  36

• 4]

  12

Six boys and 4 girls are to be seated in two separate rows with five chairs each, such that two particular girls are always together and all the girls are not in the same row. In how many ways can they be seated?

• 1]

  15 * 7!

• 2]

  20 * 8!

• 3]

  18 * 7!

• 4]

  (16 * 8! – 4! * 6!)