The rate of decay of certain substance is directly proportional to the amount present at that instant.Initially,there are 27 gms of certain substance and three hours later it is found that 8 gms are left.Find the amount left after one more hour.

The decay rate of certain substance is directly proportional to the amount present at that instant.Initially there are 27 grams of substance and 3 hours later it is found that 8 grams left.The amount left after one more hour is……….

An ice ball melts at the rate proportional to the amount of ice at any instant. If (2/3)rd quantity melts in 2 hours and if initially quantity of ice is n_0 , find the amount left after 6 hours.

The rate of growth of bacteria is proportional to the number present.If initially,there were 1000 bacteria and the number double in 1 hour,find the number of bacteria after 2 1/2 hours.Take (sqrt 2=1.414) .

The rate of increase in the numbers of bacteria culture is proportional to the number present.If initially there were 1000 bacteria and the number doubles in 1 hour,find the number of bacteria after a time of 2 1/2 hours.

A cistern is being emptied in such a way that the rate at which water is flowing out is proportional to the amount left at that instant. If half the amount flow in 7 minutes, after how much time 1/8 th of the water will be left? a)14 minutes b)21 minutes c)28minutes d)35 minutes