Several fish were accidentally released into a lake. After weeks, the number of fish is estimated to be . Determine the likely number of fish in the lake after 5 weeks. Give your answer to the nearest whole number.
The population, , of a city in year is given by the formula . Determine the year in which the population of the city was 2.1 million.
A quantity decays in time years according to the formula . If half the amount is left after 46 years, what is the value of ?