09E-28. NASA sent the Phoenix Probe to Mars in 2007/08. It traveled 423 million mi on the trip from Earth to Mars. If the mean orbital radii of the Earth and Mars are 1.496x10^8 km and 2.279x10^8 km, respectively, what is the percent difference in the average closest approach of the planet's and the distance Phoenix traveled.
Answer: 7.69x10^2 (3SD)
09E-36. The volume of water in the world's oceans is 317 million cubic miles which is 97.24% of the total water on the earth. What fraction of the earth's volume is water?
Answer: 1.25x10^-1
09E-37. The Colossus of Rhodes, one of the seven wonders of the ancient world, stood 100 ft. It was clad with bronze plate averaging 0.5 in thickness. The surface area of a man 6ft tall is 1.9 m^2. Based on this, estimate the weight of bronze used in the Colossus. The density of bronze is 8.75 g/cm^3.
Answer: 1.29x10^5
09E-38. Lenny starts with a full, 2-cup container of 30% salt solution. He divides the solution in half. To one half, he adds water to double the volume and refills the original container, discarding the leftover mixture. How many times must this procedure be done to dilute the original 30% solution down to just less than 5%?
Answer: 7 integer
09E-46. A stone mason stacks rectangular cut stones to build a wall of fixed height and length. The stones are available in different sizes but have the same shape. The cost of a stone is proportional to its volume. If the wall materials cost is $2000 when an 8-in stone is used, what is the cost of the wall when 10-in stones are used?
Answer: $2500.00
09E-56. What is the minimum value of x for the ellipse [unparseable or potentially dangerous latex formula]?
Answer: -8.11
09E-57. A backpacker is 2 miles away from a straight road and 10 miles away from a town. The road goes directly to the town. If the backpacker hikes at 3 mph off-road and 4 mph on the road, at what angle should she hike toward the road (directly towards the road is zero degrees) to get to the town as quickly as possible?
Answer: 4.86x10^1
Thanks in advance. :)