TCS Company Numerical Ability Probability

There are two boxes, one containing 21 red balls and the other containing 25 green balls. You are allowed to move the balls between the boxes so that when you choose a box at random and a ball at random from the chosen box, the probability of getting a red is maximized. This maximum probability is
(a) 0.5 (b) 0.63 (c) 0.72 (d) 0.48

Read Solution (Total 3)

1/2*(1+20/45)=65/90=.72
12 years agoHelpfull: Yes(15) No(1)

0.72
we will keep 1 red ball in 1 box and rest 20 in another box.
then total prob.=
1/2 +1/2*2/9=13/18
12 years agoHelpfull: Yes(11) No(10)
.72 option c is correct
5 years agoHelpfull: Yes(0) No(0)

TCS Other Question

You have a jar containing water absorbing marbles which will take 21 hours to set completely when fixed with white cement. There are 50 red marbles, 52 blue marbles and 63 black marbles. The jar is kept inside a dark room. What is the minimum number of marbles that you need to pick to make sure that you have a pair of marbles in each colour ?

(a)117 b)98 (c)120 (d) 114 Alok and Bhanu play the following min-max game. Given the expression N=46+X+Y-Z, where X,Y and Z are variables representing single digits (0 to 9) Alok woul like to maximize N while Bhanu would like to minimize it. Towards this end, Alok chooses a single digit number and Bhanu substitues this for a variable of her choice (X, Y or Z) Alok then chooses the next value and Bhanu the Variab le to substitute the value. Finallyu Alok proposes the value for the remaining variable. Assuming both play to their optimal strategies the value of N at the end of the game would be
37
57
64
55