Emilia's first flight lasted 328 minutes, and her second flight lasted 566 minutes. estimate the combined length of her flights by rounding to the nearest ten first and then adding the rounded numbers.

Donald has x twenty-dollar bills and 11 ten-dollar bill. how much money does donald have? write your answer as an expression.

Carl's candies has determined that a candy bar measuring 3 inches long has a z-score of +1 and a candy bar measuring 3.75 inches long has a z-score of +2. what is the standard deviation of the length of candy bars produced at carl's candies?

Tom drove 206 miles in 3.9 hours. estimate his average speed.