18) You have 90 minutes to complete at least 18 chemistry and math problems. It takes 5 minutes to complete a chemistry problem and 4 minutes for each math problem. Which is a possible solution to this situation? A) 7 chemistry problems and 15 math problems B) 9 chemistry problems and 12 math problems C) 10 chemistry problems and 10 math problems D) 12 chemistry problems and 8 math problems