Surface area & volume of spheres and hemispheres. 9 questions.

Afurniture store has 1,500 chairs in storage. a manager uses three delivery receipts to simulate samples to check 100 chairs and note the number of brown chairs. suppose the actual number of brown chairs is 1,080. about how many brown chairs are

He ! a group of farmers planned to clean 80 acres of wheat per day to finish the work on schedule. right before the work started, they received a new piece of machinery that them clean 10 more acres per day than originally planned. as a result of increased productivity in the last day before the deadline they only had to clean 30 acres. how many acres of wheat did the group of farmers have to clean?

The sum of the speeds of two trains is 720.2 mph. if the speed of the first train is 7.8 mph faster than the second train, find the speeds of each.