Quiz Discussion

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

• 1]

  12

• 2]

  15

• 3]

  18

• 4]

  -1

A number lock on a suitcase has 3 wheels each labeled with 10 digits from 0 to 9. If the opening of the lock is a particular sequence of three digits with no repeats, how many such sequences will be possible?

• 1]

  720

• 2]

  760

• 3]

  780

• 4]

  680

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

How many 3-digit numbers can be formed from the digits 2, 3, 5, 6, 7 and 9, which are divisible by 5 and none of the digits is repeated

• 1]

  5

• 2]

  10

• 3]

  15

• 4]

  20

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

Four letters are selected from the word “CAPAME” and are rearranged to form four letter words. How many words can be formed?

• 1]

  120

• 2]

  90

• 3]

  180

• 4]

  192

What is the sum of all 4 digit numbers that can be formed by the digits 1, 2, 3, 4 each exactly once

• 1]

  55566

• 2]

  66660

• 3]

  56456

• 4]

  84738

If ¹⁸C_r = ¹⁸C_r+2 ; find ^rC₅.

• 1]

  56

• 2]

  63

• 3]

  49

• 4]

  42

A basketball team of 5 players is to be selected from a group of 10 men and 8 women players. A volley ball team of 6 players is to be selected from a group of 8 men and 7 women players. Find the difference in the number of ways in which both the teams are selected, given that each team has only 2 female players.

• 1]

  1890

• 2]

  1920

• 3]

  1950

• 4]

  1990

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