Quiz Discussion

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

How many numbers can be formed from 1, 2, 3, 4, 5 (without repetition), when the digit at the unit’s place must be greater than that in the ten’s place?

• 1]

  60

• 2]

  54

• 3]

  51 / 3

• 4]

  2 x 4!

If (n + 2)! = 2550 (n!); find ’n’

• 1]

  49

• 2]

  35

• 3]

  38

• 4]

  43

What is the probability of getting at least one six in a single throw of three unbiased dice?s

• 1]

  91/216

• 2]

  1/216

• 3]

  200/216

• 4]

  17/216

If P(A)=2/5​, P(B)=3/10​ and P(A ∩ B) =51​, then P(A' | B'). P(B' | A') is equal to

• 1]

  5/6

• 2]

  5/7

• 3]

  25/42

• 4]

  1

In how many different ways can the letters of the word 'OPTICAL' be arranged so that the vowels always come together?

• 1]

  120

• 2]

  720

• 3]

  4320

• 4]

  2160

How many words can be formed from the letters of the word "SIGNATURE" so that vowels always come together.

• 1]

  17280

• 2]

  4320

• 3]

  720

• 4]

  80

A box contains two white balls, three black balls and four red balls. Balls of the same colour are distinct. The number of ways in which three balls can be drawn from the box if atleast one black ball is to be included in the draw, is

• 1]

  32

• 2]

  64

• 3]

  128

• 4]

  None Of These

Seven different objects must be divided among three people. In how many ways can this be done if one or two of them must get no objects?

• 1]

  36

• 2]

  84

• 3]

  180

• 4]

  381

In a group of 6 boys and 4 girls, four children are to be selected. In how many different ways can they be selected such that at least one boy should be there?

• 1]

  159

• 2]

  194

• 3]

  205

• 4]

  209