Q62 of 74 Page 9

The number of bacteria in a certain culture doubles very 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? nth hour?


As per question, the number of bacteria in a certain culture doubles every hour. So, they form a G.P. in which a = 30 and r = 2.

Bacteria present after 2nd hour, 4th hour and nth hour are T3, T5 and Tn+1 i.e., ar2, ar4 and arn.

i.e., 30(2)2, 30(2)4 and 30(2n) respectively.

More from this chapter

All 74 →
60
The sum of two numbers is 6 times their geometric mean. Show that the numbers are in the ratio  3 + 2 2 : 3 – 22.

61
If A and G be A.M. and G.M. respectively between two positive numbers, prove that the numbers are A ± .

63
What will Rs. 500 amounts to in 10 years after its deposit in a bank which pays annual interest rate of 10% compounded annually?

64
If A.M. and G.M. of roots of a quadratic equation are 8 and 5 respectively, then obtain the quadratic equation.