All you have to do is multiply 3/4 of a mile times two because she walked round trip. The answer is 1.5 miles
Ok, so if the angle is 120 degrees, its one third of the full cake (which is 360 degrees). So the area of the whole circle (worked out with area = pi * r^2 where r is 30) gives 900*pi, and so one third of that (because her slice is one third) is 300pi.
The angle measured from the normal to the mirror will be
.. arctan(14/11.5) ≈ 50.6°
Cost of 6 days climbing = $10 * 6 = $60
Cost of one pair of shoes = $84
Total cost = $169
So, cost of one harness = $169 - $(84+60)
harness = $169 - $144 = $25
So, your final answer is $25
