I'll help with one. You have to split the shapes into shapes you know how to find the volume of. Split the first one into two rectangles. The sides of the one on top are 3cm, 4cm, and 10-3cm, since you split it. So 10-3=7. 7*4*3 is 84. Next you find the volume of the lower rectangle. 16cm, 3cm, and 16-3cm are the sides. 16--3 is 13, so 13*4*3 = 156. add both volumes, 86+154 = 240 cm^3 is your answer.