Two cars start at the same time, but travel in opposite directions. one car's average speed is 20 miles per hour (mph). at the end of 4 hours, the two cars are 320 miles apart. find the average speed in mph of the other car. (enter an exact number.)

1 1/4 hours

step-by-step explanation:

2/4 + 2/4 + 1/4 = 5/4 or 1 1/4

step-by-step explanation:

one of the most important purposes of surface treatment is to alter surface properties according to the requirement of specific applications. for example, hydrophobic coating has been utilized on windshield and eyeglasses. gold atom monolayer on substrate has become a popular surface bioconjugation strategy.