TCS Company Category

what is summation of K=0283K(28KC)
where 28KC is the number of ways of choosing k items from 28 items?
a)256
b)3227
c)329
d)3427

Read Solution (Total 3)

option A is correct) 256
10 years agoHelpfull: Yes(2) No(2)

28CK I guess.
10 years agoHelpfull: Yes(1) No(3)
Consider (1+x)n=C0+C1x+C2x2+.....+Cnxn .......(1)
Differentiating w.r.t x we get
n(1+x)n−1=C1+2C2x+3C3x2+.....+nCnxn−1
Multiplying by x on both sides,
x.n(1+x)n−1=x.C1+2C2x2+3C3x3+.....
Now again differentiating w.r.t to x
n(1+x)n−1+n(n−1)x(1+x)n−2=C0+22C1x+32C2x2+42C3x3.....
Putting x = 1, we get
n(n+1)2n−2=C1+22C2+32C3+42C4
Now substituting n = 28
28(28+1)228−2 = 812.226 = 406.227
10 years agoHelpfull: Yes(1) No(1)

TCS Other Question

Of 38 people in my office, 10 like to drink chocolate,15 are cricket fans and 20 neither like chocolate nor like cricket, how many people like both cricket and chocolate?

a. 7
b. 10
c. 15
d. 18 A call center agent has a list of 305 phone nos of people in alphabetic order of names (but she does not have any of the names). she needs to quickly contacts deepak sharma to convey a message to him.If each call takes 2 minutes to complete, and every call is answered, what is the minimum amount of time in which she can guarantee to deliver the message to Mr.Sharma.