Q. 10
Mark the correct alternative in the following:
is equal to
A. 30
B. 31
C. 32
D. 33
Answer :
5C1 + 5C2 + 5C3 + 5C4 + 5C5
= 5C1 + 5C2 + 5C2 + 5C1 + 5C5 (5C1 = 5C4 and 5C2 = 5C3)
= 2 5C1 + 2
5C2 + 5C5
= 2 5 + 2
+ 1
= 10 + 20 + 1
= 31
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