A 66-inch candle burns down in 12 hours. After how many hours will it have burned 5 3/4 inches?

The number of nails of a given length is normally distributed with a mean length of 5.00 in, and a standard deviation of 0.03 in. find the number of nails in a bag of 120 that are less than 4.94 in. long.

Which equation results from adding the equations in this system? x+6y=9 and -x+2y=-15

W-16=-12 solve each one step equation plz