Question

The number of bacteria in a certain culture was found to be 4*10^6 at noon of one day. At noon the next day, the number was 9*10^6. If the number increased at a constant rate per hour, how many bacteria were there on the intervening midnight?

A 6*10^6 Correct Answer Incorrect Answer
B 7*10^6 Correct Answer Incorrect Answer
C 6.5*10^6 Correct Answer Incorrect Answer
D 6.9*10^6 Correct Answer Incorrect Answer
E 2*10^6 Correct Answer Incorrect Answer

Solution

Number of bacteria on the interevening midnight `= sqrt((4xx10^6)(9xx10^6))` ` = sqrt(36xx10^12)` ` = 6xx10^6`

×
×