TCS
Company
Numerical Ability
Probability
There are 6 positive and 8 negative numbers. Four numbers are choosen at random and multiplied.the probability that the product is positive is:
(a)500/1001 (b)503/1001 (c)303/1001 (d)101/1001 (e)505/1001
Read Solution (Total 5)
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- e) for positive number
6c4/14c4 + (6c2*8c2)/14c4 + 8c4/14c4 =505/1001
case1: only 4 positive no.
case2: 2 positive and 2 negative no.
case3: 4 negative no. - 13 years agoHelpfull: Yes(26) No(1)
- (6c2*8c2+6c4+8c4)/14c4
- 13 years agoHelpfull: Yes(3) No(1)
- (6c2*8c2+6c4+8c4)/14c4= 505/1001
- 6 years agoHelpfull: Yes(1) No(0)
- plz tell me how 1404 is obtained for selecting of 4 balls from 14 balls is 14c4 na
it shoult be 6006 - 12 years agoHelpfull: Yes(0) No(0)
- all four positive number = 6c4/14c4
all four negative number = 8c4/14c4
two numbers are positive and two are negative hencs probaility = 6c2*8c2/14c4
hence required probability = 6c4+8c4+(6c2*8c2)/14c4
15+70+15*28/1001
505/1001 - 4 years agoHelpfull: Yes(0) No(0)
TCS Other Question
which of the following has the highest standard deviation?
A.3,0,3,0,3,0
B.-3,-3,-3,-3,-3
C.3,3,3,3,3,3
D.-3,3,-3,3,-3,3
The average age of all boys in the class is 16.66,while the average age of all girls in the same class is 18.75.Thus the average marks of all 40 students in the class is 17.5.what is the number of girls in the class?
(a)12(b)16(c)18(d)20 (e)data insufficient