Quiz Discussion

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

Three chairs are arranged in a row facing three other chairs. 4 boys and 2 girls are to be seated on these chairs such that girls are always facing each other. In how many ways can they be seated?

• 1]

  96

• 2]

  72

• 3]

  144

• 4]

  120

How many four-digit numbers, each divisible by 4 can be formed using the digits 5, 6, 7, 8, 9, repetition of digits being allowed in any number?

• 1]

  75

• 2]

  100

• 3]

  125

• 4]

  150

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

A coin is tossed 5 times. What is the probability that head appears an odd number of times?

• 1]

  1/2

• 2]

  2/3

• 3]

  1/3

• 4]

  1

In how many ways can the letters of the word 'LEADER' be arranged?

• 1]

  360

• 2]

  720

• 3]

  120

• 4]

  None Of These

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

If ¹⁸C_r = ¹⁸C_r+2 ; find ^rC₅.

• 1]

  56

• 2]

  63

• 3]

  49

• 4]

  42

The number of circles that can be drawn out of 10 points of which 7 are collinear is

• 1]

  130

• 2]

  85

• 3]

  45

• 4]

  72

In how many ways can 10 people line up at a ticket window of a railway station?

• 1]

  36,28,800

• 2]

  34,82,800

• 3]

  33,44,800

• 4]

  33,28,800