TCS Company Numerical Ability Probability

A bag contains 4 white and 3 black balls, 2 balls are drawn at a time, randomly in succession. What is the probability that both the balls drawn are white in color, if the first ball is not replaced after the first draw.

Read Solution (Total 4)

4/7*3/6=2/7
14 years agoHelpfull: Yes(34) No(2)

4c2/7c2
14 years agoHelpfull: Yes(9) No(1)
probability of drawing first ball white is 7c4
probability of drawing second ball is 6c3 as total ball left is 6 and total white ball left is 3
ans.7c4*6c3
14 years agoHelpfull: Yes(2) No(6)
12/49
14 years agoHelpfull: Yes(1) No(7)

TCS Other Question

Subha Patel is an olfactory scientist working for International Flavors and Fragrances. She specializes in finding new scents recorded and reconstituted from nature thanks to Living Flower Technology. She has extracted fragrance ingredients from different flowering plants into bottles labeled herbal, sweet, honey, anisic and rose. She has learned that a formula for a perfume is acceptable if and only if it does not violate any of the rules listed: If the perfume contains herbal, it must also contain honey and there must be twice as much honey as herbal. If the perfume contains sweet, it must also contain anisic, and the amount of anisic must equal the amount of sweet. honey cannot be used in combination with anisic. anisic cannot be used in combination with rose. If the perfume contains rose, the amount of rose must be greater than the total amount of the other essence or essences used. Which of the following could be added to an unacceptable perfume consisting of two parts honey and one part rose to make it acceptable?

1) Two parts rose
2) One part herbal
3) Two parts honey
4) One part sweet

Variables R and S are related by the equation R=(1/S^2). Now is S is increased by 10%. What will happen to R?