On first day I put one flower in a river, 2nd day two flowers, 3rd day four flowers, 4th day eight flowers,..... On 30th day when I put flowers the river is totally covered with the flowers.
On which day the river is half covered with flowers.

• everyday he is doubling the no of flowers.........on 29 day the river is half field with flower.......now when 30 day he will double theno of flower ,river become full of flower
• 8 years agoHelpfull: Yes(5) No(1)
• on 30 th day : 1+2+2^2+2^3+.......+2^29 = 1+r+r^2+......+r^n-1
  sum of the terms= (1-r^n)/(1-r) = 2^30
  30 th day it is full with 2^30 flowers
  therefore it has (2^30)/2 =2^29 flowers on 29th day
  
• 9 years agoHelpfull: Yes(3) No(5)