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Question
The number of bacteria in a culture doubles every hour. If there were 50 bacteria originally in the culture, how many bacteria will be there at the end of 5thhour?
Solution
a = 50
r = 2
n = 5
we have,
tn = a. r(n - 1)
To find the number of bacteria at the end of the 5th hour
(i.e, to find the number of bacteria at the beginning of the 6th hour, i.e, to find t6.)
t6 = ar5
= `50 × (2)5
= 50 × 32
t6 =1600
∴ After the 6th hour 1600 bacteria will be there in the culture.
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