2 divided by 5/12 = ?

( Can't be a decimal if that makes sense)

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.

Which of the following vectors are orthogonal to (2,1)? check all that apply

Can someone me with my math problem pls my teacher is on my back about this