Percent and Interest Problems

Daniel invested a total of \(\$10,000\) for a period of one year. Part of the money he put into an investment that earned 6 percent simple interest, and the rest of the money into an investment that earned \(8\) percent simple interest. How much money did he put into the investment that earned \(6\) percent?

1) The total interest earned on the \(\$10,000\) for the year was \(\$640\)

2) The dollar value of the investment that earned 6 percent was four times the dollar value of the investment that earned \(8\) percent

The OA is D