One computer printer can print a company's weekly payroll checks in 60 min. A second
printer would take 90 min to complete the job. How long would it take the two printers,
operating together, to print the checks.
Smart people can you help me again?

If a 36 inch yardstick casts a 21 foot shadow, how tall is a building whose shadow is 168 feet? what is the scale factor

Kyle and elijah are planning a road trip to california. their car travels 3/4 of a mile per min. if they did not stop driving, how many miles could kyle and elijah drove in a whole day? ? 1 day = 24 hours. plzzz write a proportion i will give you 100 points

What is the value of x in the equation7x+2y=48 when y=3