40 is what percent of 160?

Acar started driving from city a to city b, distance between which is 620 miles, at a rate of 60 mph. two hours later a truck left city b and started moving towards city a at a rate of 40 mph. how many hours after the truck's departure will the two meet?

Which will form a composite function?

Write a ratio and a percent for the shaded area. it is 3x3 and 5x5 grid there is 6 shaded out of a. 6 over 25 , 30% b. 3 over 50 , 6% c.6 over 25 , 24% d. 3 over 10 , 30%