Mammals and Math - The Problems
October 13, 2008

Last week news headlines read “1/4 of the world’s mammals endangered”… here are a few questions about a few of the mammals on that list.

Blue Whale Facts:

Average weight: 200,000 to 300,000 pounds

Average length in the Southern Hemisphere: 90 – 100 feet
Average length in the Northern Hemisphere: 75 – 80 feet

Average speed: 14 miles per hour (with bursts as fast as 30 mph)

Dive depth and time: up to 1,640 feet, dives last from 10 to 20 minutes

QUESTION: Nelly, a blue whale, begins diving below the surface of the water at an angle of 45 degrees and at a rate of 15 mph. If she continues on this path at that constant rate of descent for 5 minutes, how many miles below the surface of the water will she be? Express your answer as a common fraction in simplest radical form.

Average Weight: 12.5 lb for females, 18.3 lb for males

Where they live: the cloud forests of the Peruvian Andes

QUESTION: A particular family of yellow-tailed woolly monkeys had a 3:4 male to female ratio. Then 3 new baby boy monkeys were born (and no females were born) which resulted in there being an equal number of males and females. How many monkeys were in the family of monkeys before the 3 new baby monkeys were born?

Average Weight: 250 pounds in the wild for males, while females rarely reach 220 pounds

Average Height: 2 – 3 feet tall at the shoulder (on all four legs), and reach 4 – 6 feet long. (About the size of an American black bear)

Average Food Intake: 20 – 40 pounds of bamboo per day

QUESTION: The National Zoo's giant panda Mei Xiang gave birth to a cub on July 9, 2005. On August 2, at his first exam, he weighed 1.82 pounds, and had a total body length of 12 inches. One week later, at the cub's second exam, he weighed 2.6 pounds, and his total body length was 14 1/4 inches. By what percent did the cub’s weight increase during the week between his first and second exam? Express your answer to the nearest whole number.