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

• 2+4+8+16+32+64+128+256+512+1024=2046 is the number of his ancestors during the ten generations preceding his own.
• 12 years agoHelpfull: Yes(6) No(0)
• the generation as it goes back is on GP.the initial difference is 2 so 2^10=1024
• 12 years agoHelpfull: Yes(2) No(2)
• a person means he is the 1st generation
  so the series is 1,2,4,8....
  2^0,2^1,2^2,2^3,...
  so, the 10th generatyion has 2^9
  hence the answer is 512
• 12 years agoHelpfull: Yes(0) No(2)
• Here we can use Sn method,
  That is,
  Given: a=2 , r=2 and n=10
  Sol:
  Using Sn = a (r^n - 1)÷r-1
  So,
  S10 = 2 (2^10 - 1) = 2046
  Hence, no. of ancestors preceding is 2046
• 8 years agoHelpfull: Yes(0) No(0)