A woman invests $15000 in 2 separate investment accounts.

Question

One account earns 5.1%, one earns 4.2% simple interest.
If she earns $21 in interest total, how much did she earn from each account.

I keep getting x to be 67,666.67 by getting to this equation:
.051x + .042(15000-x) = 21

Very confused.

Answer 1

That's because there's a mistake in the problem.

Even if it were all invested at 4.2%, she'd earn .042*15000 = $630 in interest.

That $21 interest is bogus. It must be $2100 or something.