There are 5 milliliters of compound a used for every 4 milliliters of compound b. if a chemist wants to make 495 milliliters, how many milliliters of compound a are needed

Talia took the bus from her home to the bank and then walked back to her home along the same route. the bus traveled at an average speed of 40 km/h and she walked at an average speed of 5 km/h. to determine the time, x, that it took talia to walk home, she used the equation 40(0.9 – x) = 5x. the time of trip 2 is hours. the distance of trip 1 is km.