The units digit f a three-digit-number is twice the tens digit. If the digits were reversed, the number is reduced[..]

Car A can travel a circular track in 120 seconds while Car B in 80 seconds. If they start from the same point but[..]

Two airplanes left airports which are 960 km apart and flew toward each other. One plane flew 32 kph faster than the[..]

Peter is 36 years old. Peer is twice as old as Jun was when Peter was as old as Jun now. How old is Jun?

A doctor's age 8 years ago is two-thirds his age 13 years hance. How old is he now?

A 20% acid solution is Ro be mixed with 50% acid solution I. Order to get 600 ounces of a 30% acid solution. How[..]

One number is 4 less than three times the second number, their total is 64. Find the numbers

A jogger ran 3 miles then decreased her speed by 1mph and ran 4miles. Her total time was 1 3/4 hours.Find her speed[..]

A revenue R received for selling x stereos is given by the formula R=-1/5x^2+80x-1000. How many stereos must be[..]

in a set of 100 act scores, where the mean is 22 and the standard deviation is 3.32, how many scores are expected to[..]