What is the greatest multiple of 10 that can be expressed using only the numbers 2,2,3,5 each exactly once, with any or all of the operations, +*,divide, exponentiation, parentheses. express your answer in scientific notation.

Find the number of positive three-digit even integers whose digits are among 9, 8, 7,5, 3, and 1.

Acircular city park has a sidewalk directly through the middle that is 111 - feet long. if each bag of fertilizer covers 50 square feet, then determine how many bags of fertilizers the parks and recreation department needs to use to cover the circular park. ignore all the sidewalks around and through the park.

An automated water dispenser fills packets with one liter of water on average, with a standard deviation of 5 milliliter. the manual says that after a year of operation the dispenser should be tested to see if it needs recalibration. a year later a number of filled packets are set aside and measured separately. it is found that the average packet now contains about 0.995 liters. does the dispenser need calibration? explain your answer.