Question 1 - answer is 4) x and y are only parts of 40,000 dollars so adding them gives again 40000, and then interest is addition of the actual percentages of each parts of 40,000.Question 2 - answer 1) simple. Question 3 - answer 1) - for a rectangle, 2L + 2W = 7.8. Multiply both sides by 2 to get 4L + 4W = 15.6. Now 4L = 9W. So 9W + 4W = 15.6. So W=1.2. Using this value, solve for L to get L=2.7. Ratio of L/W = 2.2. Check each option to see that 4L = 9W fits the best because L/W = 9/4 which is 2.2Question 4 - answer 4) against headwind means negative sign. with tailwind is plus sign. So going to Bragg means 1.5c - 1.5W = 25 (speed x time = distance) and coming back would be simply c + w = 25.