How do you find the height of a trapezoid

What is the volume of a rectangular prism if the length is 10.4 mm the width is 5 mm in the height is 8 mm

Last year, a state university received 3,560 applications from boys. of those applications, 35 percent were from boys who lived in other states. part a)how many applications did the university receive from boys who lived in other states? part b)applications to the university from boys represented 40percent of all applications. how many applications did the university receive in all? i don't how to do part b so me and plz tell how you got your answer

15m is what percent of 60m; 3m; 30m; 1.5 km? the last one is km not m