Answer:
$ 2,600 was invested at 4% and $ 3,600 was invested at 9%.
Step-by-step explanation:
Given that in investing $ 6,200 of a couple's money, a financial planner put some of it into a savings account paying 4% annual simple interest, and the rest was invested in a riskier mini-mall development plan paying 9% annual simple interest, and the combined interest earned for the first year was $ 428, to determine how much money was invested at each rate, the following calculation must be performed:
3000 x 0.04 + 3200 x 0.09 = 408
2500 x 0.04 + 3700 x 0.09 = 433
2600 x 0.04 + 3600 x 0.09 = 428
Therefore, $ 2,600 was invested at 4% and $ 3,600 was invested at 9%.