Question
Question: \(\sum_{k = 0}^{10}{20C_{k}}\) =...
∑k=01020Ck =
A
219 + 2120 C10
B
219
C
20C10
D
None of these
Answer
219 + 2120 C10
Explanation
Solution
S = 20C0 + 20C1 + 20C2 + ……… 20C10
2S = (20C0 + 20C1 + … 20C10) + 20C10
2S = 220 + 20C10
S = 219 + 21 20C10