Bernie has $16000 invested, part at 3% and the remainder at 5%. If the yearly interest on each investment is the same, how much interest does he receive each year? My teacher asked me to do this by making a system and solving. It would be nice to get a good explanation.

"curse these trig-loving pirates! " devora mutters as she looks at the map. then, after thinking for a moment, she walks back to the entrance of the secret cave, measuring 48 meters along the way. after performing a calculation, devora walks back to the empty treasure, faces the entrance, and turns a certain number of degrees to her left before walking 89 meters to the treasure. supposing that the angle at the cave entrance is acute and that devora's calculations were correct, how many degrees did she turn?