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 rectangles can be formed out of a chess board ?

• 1]

  1740

• 2]

  1230

• 3]

  1296

• 4]

  204

Two cards are drawn together from a pack of 52 cards. The probability that one is a spade and one is a heart, is

• 1]

  3/20

• 2]

  29/34

• 3]

  47/100

• 4]

  13/102

From among the 36 students in a class, one leader and one class representative are to be appointed. In how many ways can this be done?

• 1]

  1360

• 2]

  1060

• 3]

  1160

• 4]

  1260

A person tosses an unbiased coin. When head turns up, he gets Rs.8 and tail turns up he loses Rs.4. If 3 coins are tossed, what is probability that he gets a profit of Rs.12?

• 1]

  3/8

• 2]

  5/8

• 3]

  3/4

• 4]

  1/8

Two variants of the CAT paper are to be given to 12 students. In how many ways can the students be placed in two rows of six each so that there should be no identical variants side by side and that the students sitting one behind the other should have the same variant. Find the number of ways this can be done

• 1]

  2 x ¹²C₆ x (6!)²

• 2]

  2 x 6! x 6!

• 3]

  2 x ¹²C₆ x 6!

• 4]

  None of these

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, B, C, and D are four points, any three of which are non-collinear. Then, the number of ways to construct three lines each joining a pair of points so that the lines do not form a triangle is

• 1]

  7

• 2]

  8

• 3]

  9

• 4]

  24

If four dice are thrown together, then what is the probability that the sum of the numbers appearing on them is 25 ?

• 1]

  0

• 2]

  1/2

• 3]

  1

• 4]

  1/1296

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