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

A speaks truth in 75% cases and B in 80% of the cases. In what percentage of the cases are they likely to contradict each other, narrating the same incident?

• 1]

  5%

• 2]

  15%

• 3]

  35%

• 4]

  45%

A biased coin in tossed thrice. What is the probability that heads turns out at least twice considering that the probability of a head is 60%?

• 1]

  0.648

• 2]

  0.234

• 3]

  0.348

• 4]

  .839

If ,​, are probabilities of three mutually exclusive events, then

• 1]

  

• 2]

  

• 3]

  

• 4]

  None Of These

A box contains 2 white balls, 3 black balls and 4 red balls. In how many ways can 3 balls be drawn from the box, if at least one black ball is to be included in the draw?

• 1]

  32

• 2]

  48

• 3]

  64

• 4]

  96

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

• 1]

  12

• 2]

  15

• 3]

  18

• 4]

  -1

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

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

How many words, with or without meaning, can be formed using all letters of the word EQUATION using each letter exactly once?

• 1]

  38,320

• 2]

  39,320

• 3]

  38,400

• 4]

  40,320

There are three rooms in a motel: one single, one double, and one for four persons. How many ways are there to house seven persons in these rooms?

• 1]

  7! / 1! 2! 3! 

• 2]

  7! 

• 3]

  7! / 3

• 4]

  7! / 3!