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Over the course of the last year, Andrew's investment account has grown by 2.9%. Currently, Andrew has $2,778.30 in this account. What was the balance in his account one year ago, before this gain? One year ago the balance was Ken invested $8,000 in two accounts. At the end of a year, one account had made a 5% gain, and the other had made a 4% gain. All together, Ken made 8360 in interest. How much money did Ken invest in each account? The table below may help you organize information before you write an equation. If we let I be the amount of money invested in the 5% account... Rate * Principal Interest 5% Investment 0.05 0.052 4% Investment 0.04 0.04(8000 - 2) Organize data with a table According to the table, the total interest that Ken earned is dollars. 8000 - Now set up and solve an equation to find how much Ken invested in each account. at 496 at 5% and Ken invested Your banker tells you that your (one time) investment will double every 12 years. You figure that the effective annual interest rate is percent. The effective annual interest rate is the profit you obtain at the end of each of year, figured as a percentage. Of course you realize that each year you receive interest also for the interest earned in the preceding years. Hint: Call the unknown interest rate p. Every year you multiply your capital with (1+p/100)