Quiz Discussion

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 speaks truth in 75% cases and B in 80% of the cases. In what percentage of the cases are they likely to contradict each other, narrating the same incident?

• 1]

  5%

• 2]

  15%

• 3]

  35%

• 4]

  45%

If A, B and C are mutually exclusive and exhaustive events of a random experiment such that P(B)=3/2​P(A) and P(C)=1/2​P(B), then P(A∪C)=

• 1]

  3/13

• 2]

  6/13

• 3]

  7/13

• 4]

  10/13

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

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!

A teacher has to choose the maximum different groups of three students from a total of six students. Of these groups, in how many groups there will be included in a particular student?

• 1]

  12

• 2]

  10

• 3]

  8

• 4]

  6

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

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

If ¹⁸C_r = ¹⁸C_r+2 ; find ^rC₅.

• 1]

  56

• 2]

  63

• 3]

  49

• 4]

  42

How many rectangles can be formed out of a chess board ?

• 1]

  1740

• 2]

  1230

• 3]

  1296

• 4]

  204