What is the answer to both the questions?

Fred bought 3 cd’s for $16.50 is this multiplication division subtraction or addition

Question 1(multiple choice worth 1 points)(07.06 mc)a group of students must collect at least $150 to organize a science fair. they have already collected $30. which graph best represents all remaining amounts of money, in dollars, that thestudents should still collect to organize the science fair? -210 -180 -150 - 120 -90-60 -300306090 120 150 180 210-210 -180 -150 - 120 -90 -60 -30 0 30 60 90 120 150 180 210-210 -180-150 - 120 -90-60-300 30 60 90 120 150 180 210-210 -180 -150 - 120.90 -60 -30 0 30 60 90 120 150 180 210

The water has been on the stove y=9.5x+62.1 after how many minutes will the tempature be 138.1 f