Quiz Discussion

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

There are 20 people among whom two are sisters. Find the number of ways in which we can arrange them around a circle so that there is exactly one person between the two sisters.

• 1]

  2! x 19!

• 2]

  18!

• 3]

  18! x 2!

• 4]

  19!

In a lottery, there are 10 prizes and 25 blanks. A lottery is drawn at random. What is the probability of getting a prize?

• 1]

  1/10

• 2]

  2/5

• 3]

  2/7

• 4]

  5/7

There are three rooms in a motel: one single, one double, and one for four persons. How many ways are there to house seven persons in these rooms?

• 1]

  7! / 1! 2! 3! 

• 2]

  7! 

• 3]

  7! / 3

• 4]

  7! / 3!

12 person are seated at a round table. Number of ways of selecting 2 persons not adjacent to each other is

• 1]

  10

• 2]

  11

• 3]

  54

• 4]

  48

In how many different ways can the letters of the word 'CORPORATION' be arranged so that the vowels always come together?

• 1]

  50400

• 2]

  2430

• 3]

  6540

• 4]

  12800

If P(A)=2/5​, P(B)=3/10​ and P(A ∩ B) =51​, then P(A' | B'). P(B' | A') is equal to

• 1]

  5/6

• 2]

  5/7

• 3]

  25/42

• 4]

  1

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!)

One red flower, three white flowers, and two blue flowers are arranged in a line such that
I. No two adjacent flowers are of the same color.
II. The flowers at the two ends of the line are of different colors.
In how many different ways can the flowers be arranged?

• 1]

  2

• 2]

  4

• 3]

  6

• 4]

  10

In how many ways can a group of 5 men and 2 women be made out of a total of 7 men and 3 women?

• 1]

  63

• 2]

  90

• 3]

  126

• 4]

  45