Exams

Given that there are three blue marbles, four red marbles, six green marbles and two yellow marbles.

Probability that both marbles are blue = ³C₂/¹⁵C₂ = (3 x 2)/(15 x 14) = 1/35

Probability that both are yellow = ²C₂/¹⁵C₂ = (2 x 1)/(15 x 14) = 1/105

Probability that one blue and other is yellow = (³C₁ x ²C₁)/¹⁵C₂ = (2 x 3 x 2)/(15 x 14) = 2/35

Required probability = 1/35 + 1/105 + 2/35 = 3/35 + 1/105 = 1/35(3 + 1/3) = 10/(3 x 35) = 2/21

In a circle of n different persons, the total number of arrangements possible = (n - 1)!
Total number of arrangements = n(S) = (15 – 1)! = 14 !
Taking three persons as a unit, total persons = 13 (in 4 units)
Therefore no. of ways for these 13 persons to around the circular table = (13 - 1)! = 12!
In any given unit, 3 particular person can sit in 3!. Hence total number of ways that any three person can sit =
n(E) = 12! X 3!
Therefore P (E) = probability of three persons sitting together = n(E) / n(S) = 12! X 3 ! / 14!
= 12!x3x2 / 14x13x12! = 6/14x13 = 3/91

Political stalwarts Sharad Pawar, Murli Manohar Joshi and the late Lok Sabha Speaker P A Sangma, cricketer Virat Kohli and Bollywood singer Anuradha Paudwal were among the 39 people who conferred this year’s Padma awards.

Here total number of boys in the row = 11 + 19 = 13 + 17 = 30

Here after exchanging the places of Haran & Manoj 

=> Manoj replaces Harans place of 11th from left 

But in the question he asked Manoj's place from right = 30 - 11 = 19th place.

A spoofing attack is a situation in which one individual or program effectively disguises or mask as another by falsifying information and thereby gaining up an ill-conceived advantage. It may use for stealing password or IP addresses.

1 + 1 = 121 = 1x1 1+1 1x1

1 + 2 = 134 = 1x1 1+2 2x2

2 + 2 = 444 = 2x2 2+2 2x2

3 + 2 = 954 = 3x3 3+2 2x2

3 + 3 = ?   

Similarly, 3x3 3+3 3x3 = 969