Quiz Discussion

Ten participants are participating in a competition. In how many ways can the first three prizes be won?

• 1]

  920

• 2]

  680

• 3]

  720

• 4]

  820

If ¹⁸C_r = ¹⁸C_r+2 ; find ^rC₅.

• 1]

  56

• 2]

  63

• 3]

  49

• 4]

  42

How many integers between 1000 and 10000 have no digits other than 4, 5, or 6?

• 1]

  91

• 2]

  71

• 3]

  51

• 4]

  81

How many 4-letter words with or without meaning, can be formed out of the letters of the word, 'LOGARITHMS', if repetition of letters is not allowed?

• 1]

  40

• 2]

  400

• 3]

  5040

• 4]

  2520

Six boys and 4 girls are to be seated in two separate rows with five chairs each, such that two particular girls are always together and all the girls are not in the same row. In how many ways can they be seated?

• 1]

  15 * 7!

• 2]

  20 * 8!

• 3]

  18 * 7!

• 4]

  (16 * 8! – 4! * 6!)

Find the probability that a leap year selected at random will contain 53 Sundays

• 1]

  2/7

• 2]

  3/7

• 3]

  2/3

• 4]

  5/6

The value of  ⁷⁵P₂

• 1]

  5450

• 2]

  5555

• 3]

  5550

• 4]

  5656

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

A five-letter word is to be formed from a group of 5 vowels and 4 consonants, using at least one vowel and at least one consonant. In how many ways the word having a greater number of consonants than vowels can be formed?

• 1]

  40

• 2]

  42

• 3]

  45

• 4]

  52

A box contains 5 green, 4 yellow and 3 white marbles. three marbles are drawn at random. What is the probability that all they are not of the same colour?

• 1]

  3/44

• 2]

  3/55

• 3]

  52/55

• 4]

  41/44