A person has 2 parents, 4 grandparents, 8 great grand parents, and so on. Find the number of his ancestors during the ten generations preceding his one.

Options

A. 1023
B. 1024
C. 2046
D. None of the above

Answer

C

Explanation

Number of ancestors during the ten generations preceding his own generation



= Sum of 10 terms of the G.P. 2,4,8,..

.
Number of ancestors `S_10=2(2^10−1)/(2−1)`


=`2(1024−1)`

...