1.The number of insects in a colony doubles every month. if there are now 1000 insects in the colony, about how many were in the colony three months ago?
2. A certain barangay has a population of 7,000 in 2000. The constant rate of increase is 12% per annum. What will be the population of the barangay in 2020?
3. In nuclear test explosion, some strontium-90 is released. This substance has a half-life of 32 years. What part of strontium-90 remains after 6 years?

Please paki answer po with solution. TIA​