what is summation of [3^k(28Ck)] (summation range 28 to k=0) where 28Ck is the number of ways of choosing k items from 28 items??  Answers: A) 4^28 B) 4^27 C) 4^26 D) 4^25 E) 4^24
The expansion of (1+x)^n=nC0 x^0+nC1 x^1+nC2 x^2+......   putting the value of x=3 and n=28 we get   (1+3)^28=28C0 3^0+28C1 3^1+28C2 3^2+28C3 3^3.......   which is the given summation we need to find hence,   ans= 4^28   4^28NSWER:4^28
<result>A</result>
what is summation of [3^k(28Ck)] (summation range 28 to k=0) where 28Ck is the number of ways of choosing k items from 28 items??