The population of a bacteria culture doubles every 2 minutes Approximately how many minutes will it take for the population

Initial population of bacteria = 1000
After 2 minutes = 2000
After 4 minutes = 4000
See any pattern?
1000 2000 4000 8000.....5,00,000

a1 = 1000 a1 = 1000 x 1
a2 = a1 x 2 = 1000 x 2^1 (ar where r = 2)
a4 = a2 x 2 = 1000 x 2^2

an = 1000 x 2^n
500000 = 1000 x 2^n
2^n = 500
Approximate value of n = 9
9 two minutes period or 18 minutes
Answer is D.
11 years agoHelpfull: Yes(13) No(1)
using GP series:
1st term*(((common ratio)^n)-1)/(common ratio-1))=last term
=>1k*((2)^n)-1)/(2-1))=500k
=>n=9(nearly)
hence no. of minutes=9*2=18 minutes
11 years agoHelpfull: Yes(2) No(0)
for the first 2 mins,it will become 2,000, total 2 mins
for the second 2 mins,it will become 4,000,total 4 mins
and so,..,.,
,.,.
,,,.
.,.
on the 10 2 mins,it will become 512,000 so total 20 mins
11 years agoHelpfull: Yes(0) No(9)
approx 18 minutes
11 years agoHelpfull: Yes(0) No(2)
18 mins....
11 years agoHelpfull: Yes(0) No(3)
[d] 18 minutes
11 years agoHelpfull: Yes(0) No(0)
d)18mins.....
11 years agoHelpfull: Yes(0) No(1)
9*2min=18 min
11 years agoHelpfull: Yes(0) No(1)

The population of a bacteria culture doubles every 2 minutes. Approximately how many minutes will it take for the population to grow from 1,000 to 500,000 bacteria?
option
(A) 10
(B) 12
(C) 14
(D) 18
(E) 20