An industrial filter removes 90% of the particulate matter from the exhaust gases of a furnace. How many filters must the gas pass through in order to remove 99.9% of the particles before releasing the gases to the outside air? (Exponential decay/growth)

Atrain leaves little? rock, arkansas, and travels north at 90 kilometers per hour. another train leaves at the same time and travels south at 80 kilometers per hour. how long will it take before they are 680 kilometers? apart?

The ideal weight of a nickel is 0.176 ounce. to check that there are 40 nickels in a roll, a bank weighs the roll and allows for an error of 0.015 ounce in total weight

The table below shows the number of free throw shots attempted and the number of shots made for the five starting players on the basketball team during practice. each player's goal is to make 80% of her shots. players number of free throws made free throw attempts kelly 16 20 sarah 25 30 maggie 31 40 liz 44 50 kim 47 60 how many players made at least 80% of their shots? round to the nearest percent.