Standard Five – Top Level Problems Prompt: Grandma had to cook her biscuits for exactly 10 minutes. However, the only times she had were a 4 minute egg timer and a 7 minute egg time. How did she use the two egg timers to measure exactly 10 minutes? Math’s Mate Gold, J.B. Wright, 1995 Prompt: The Gibb’s Hill Lighthouse, Southampton, Bermuda, in operation since 1846, stands 117 feet high on a hill 245 feet high, so its beam of light is 362 feet above sea level. A brochure states that the light itself can be seen on the horizon about 26 miles distant. Verify the correctness of this information. Precalculus, Sullivan and Sullivan, 2006 Prompt: To measure the height of Lincoln’s caricature on Mt. Rushmore, two sightings 800 feet from the base of the mountain are taken. If the angle of elevation to the bottom of Lincoln’s face is 32 degrees and the angle of elevation to the top is 35 degrees, what is the height of Lincoln’s face? Precalculus, Sullivan and Sullivan, 2006 Prompt: A cone-shaped tent is made from a circular piece of canvas 24 feet in diameter by removing a sector with central angle of 100 degrees and connecting the ends. What is the surface area of the tent? Precalculus, Sullivan and Sullivan, 2006 Prompt: The maximum safe load for a horizontal rectangular beam varies jointly with the width of the beam and the square of the thickness of the beam and inversely with its length. If an 8-foot beam will support up to 750 pounds when the beam is 4 inches wide and 2 inches thick, what is the maximum safe load in a similar beam 10 feet long, 6 inches wide, and 2 inches thick? Precalculus, Sullivan and Sullivan, 2006