Quiz Discussion

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

How many words can be formed from the letters of the word "SIGNATURE" so that vowels always come together.

• 1]

  17280

• 2]

  4320

• 3]

  720

• 4]

  80

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

• 1]

  12

• 2]

  15

• 3]

  18

• 4]

  -1

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 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

Two dice are thrown simultaneously. What is the probability of getting two numbers whose product is even?

• 1]

  1/2

• 2]

  3/4

• 3]

  3/8

• 4]

  5/16

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

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

• 1]

  

• 2]

  

• 3]

  

• 4]

  None Of These

How many natural numbers can be made with digits 0, 7, 8 which are greater than 0 and less than a million?

• 1]

  496

• 2]

  728

• 3]

  486

• 4]

  1084

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