Kevin C.

We’ll call a set of numbers un-average if the average of any two numbers in the set is not in the set. So {1, 3, 6, 7, 10} is un-average, but {1, 3, 6, 7, 9} is not. What is the largest set of... more

a truck enters a highway driving 60 mph. a car enters the highway at the same place 9 minutes later and drives 74 mph in the same direction. from the time the car enters the highway, how long will... more

money is borrowed at 15% simple interest. after one year, $1129.30 pays off the loan. how much was originally borrowed?

A blood test for a certain disease tests positive 90% of the time, when the disease is present. The same test shows up positive 2.5% of the time, when the disease is not present. 2% of the... more

We’ll call a set of numbers un-average if the average of any two numbers in the set is not in the set. So {1, 3, 6, 7, 10} is un-average, but {1, 3, 6, 7, 9} is not. What is the largest set of... more

Determine whether or not the procedure described results in a binomial distribution. Identify why or why not. Four hundred different voters in a region with two political parties; A and B, are... more

When calculating a sample variance a factor of (N-1) appears instead of N (see http://en.wikipedia.org/wiki/Sample_variance#Population_variance_and_sample_variance ). Does anybody have an intuitive... more

SKYSCRAPERS While working on a high-rise building, a window washer is trying to mix a diluted cleaning solution that is 55% soap. He is adding an 80% soap solution to 1 liter of 40% soap solution.... more

A city council consists of eight Democrats and eight Republicans. If a committee of four people is​ selected, find the probability of selecting two Democrats and two Republicans.