Members of the fire department lean a 30-foot ladder against a building. the side of the building is perpendicular to the level ground so that the base of the ladder is 10 feet away from the base of the building. to the nearest foot, how far up the building does the ladder reach?
can you explain with some details?

Add the fractions, and simply the result to lowest terms. 2/3 + 2/7= ?

Assume that the weights of quarters are normally distributed with a mean of 5.67 g and a standard deviation 0.070 g. a vending machine will only accept coins weighing between 5.48 g and 5.82 g. what percentage of legal quarters will be rejected? round your answer to two decimal places.

Mozart lenses inc. recently introduced seelites, a thinner lens for eyelasses. of a sample of 800 eyeglass wearers, 246 said they would purchases their next pair of eyeglasses with the new lenses. lenses inc. estimates that the number of people who purchase eyeglasses in a year is 1,700,000. most eyeglasses wearer buy one new pair of eyeglasses a year. what is the annual sales potential for the new lenses.