# Problem of the Day: 2/4/13

Darren is thinking of two numbers. Their sum is 21, and their product is 108. What is their positive difference?

Solution to yesterday’s problem:

First we need to find the circumference of the garden. The formula for circumference is $C=\pi d$. Substituting 20 for d, we get a circumference of 62.8319 feet. Each shrub is 6 inches in diameter, which means 2 shrubs will fit on one foot of the border. Double 62.8319 is 125.6638, so we can reasonably fit 125 shrubs around the border of the garden.