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The number of bacteria in a certain cult...

The number of bacteria in a certain culture doubles every hour. If there were 30 bacteria present in the culture originally, how many bacteria will be present at the end of 2nd hour, 4th hour and nth hour?

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The correct Answer is:
N/a

Here `a=30,r=2`
G.P. `=a,ar,ar^(2),ar^(3),…..`
No. of bectaria at the end of two hours. = 3rd term
`=ar^(2)=30(2)^(2)=120`
No. of bacteria at the end of 4th hour= 5th term
`=a*r^(4)=30(2)^(4)=480`
No. of bacteria at the end of nth hour =(n+1)th term
`=a*r^(n)=30*(2)^(n)`
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NAGEEN PRAKASHAN ENGLISH-SEQUENCE AND SERIES-Exercise 9.3
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  2. The sum of first three terms of a G.P. is 16 and the sum of the next ...

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  3. Given a G.P with a=729 and 7th term 64,determine S(7).

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  4. Find a G.P. for which sum of the first two terms is - 4and the fifth ...

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  5. If the 4^(t h), 10^(t h)and 16^(t h)terms of a G.P. are x, y and z, r...

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  6. Find the sum to n terms of the sequence 8,88,888,8888,……

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  7. Find the sum of the products of the corresponding terms of the sequen...

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  8. Show that the products of the corresponding terms of the sequence a,...

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  9. Find four numbers forming a geometric progression in which the third ...

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  10. If the p^(t h),q^(t h)and r^(t h)terms of a GP are a, b and c, respec...

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  11. If the first and the nth term of a G.P. are a and b, respectively, and...

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  12. Show that the ratio of the sum of first n terms of a G.P. to the su...

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  13. If a, b, c and d are in G.P. show that (a^2+b^2+c^2)(b^2+c^2+d^2)=(a b...

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  14. Insert two number between 3 and 81 so that the resulting sequence i...

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  15. If (a^(n+1)+b^(n+1))/(a^n+b^n) is the A.M. between a and b . Then, fin...

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  16. The sum of two numbers is 6 times their geometric mean, show that numb...

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  17. If A and G be A.M. and GM., respectively between two positive numbers...

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  18. The number of bacteria in a certain culture doubles every hour. If ...

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  19. What will Rs 500 amounts to in 10 years after its deposit in a bank...

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