The population of a country doubles in 50 years. How many years will it be five times as much? Assume that the rate of increase is proportional to the number inhabitants. (hint: log2=0.6931, log5=1.6094)

In a culture , the bacteria count is 1,00,000. The number is increased by 10% in 2 hours. In how many hours will the count reach 2,00,000. If the rate of growth of bacteria is proportional to the number present ?

The population of a village increases continuously at the rate. proportional to the number of its inhabitants present at any time. If the population of the village was 20000 in 1999 and 25000 in the year 2004, what will be the population of the village in 2009 ?

How many numbers lying between: 100 and 1000 can be formed with the digits 0,1,2,3,4,5 if the repetition of the digits is' not allowed?

In a bank, principal increases continuosly at the rate of r% per year. Find the valueof r if Rs. 100 double itself in 10 years. (log_e 2 = 0.6931)

How many 3-digit numbers can be formed from the digits 1,2,3,4 and 5 assuming that repetition of the digits is not allowed

How many 3-digit numbers can be formed from the digits 1,2,3,4 and 5 assuming that repetition of the digits is allowed?

Rate contant k_2 of a reaction at 310 K is two time of its rate constant k_1 at 300 K.Calculate activation energy of the reaction.(log 2=0.3010,log 1=0)