Question
A synthetically developed microorganism multiplies continuously by giving birth to two new cells once in every minute. At time t=0, a single such new micro-organism is placed in a petridish. If each microorganism lives for exactly 25 minutes, then find the total number of live microorganisms in the dish at the end of the 20th minute?
Answer: Option D
:
D
Double substitution:
Step 1- Rewrite the answer options in terms of n (here, n=20)
a)3n−12b)3n+1−12c)2n+1−1d)3n
Let the single organism be called A0. At t=2, the number of new microorganisms present would look as follows:
Thus, at t=2, there are 9 microorganisms alive. Put t=2 in the answer options, and check where you are not getting 9. Eliminate those options.
Only option (d) gives 9. Answer is option (d).
Was this answer helpful ?
:
D
Double substitution:
Step 1- Rewrite the answer options in terms of n (here, n=20)
a)3n−12b)3n+1−12c)2n+1−1d)3n
Let the single organism be called A0. At t=2, the number of new microorganisms present would look as follows:
Thus, at t=2, there are 9 microorganisms alive. Put t=2 in the answer options, and check where you are not getting 9. Eliminate those options.
Only option (d) gives 9. Answer is option (d).
Was this answer helpful ?
More Questions on This Topic :
Latest Videos
Latest Test Papers
Submit Solution