A rectangular lot 50 feet by 100 feet is surrounded on all sides by a concrete walk 5 feet wide. Find the number of square feet in the surface of the walk.
If you have 50 green , 50 orange, and 50 yellow jelly beans, how many bags can you fill for Halloween each containing 2 green, 3 orange, and 4 yellow jelly beans?
A word processing operator typed 44 words per minute. After practice, the operator's speed increased to 55 words per minutes. By what percent did the operator's speed increase?