This is a right solid meaning that the area of the base doesn't change at all as you go up the shape. To find the volume of a right solid, multiply the area of the base times the height.
height area of base Volume
v v v
7 x (4 x 2 + 3 x 2 + 3 x 2) = 7 x (8 + 6 + 6) = 7 x 20 = 140 cm^3
To find aurface area we must add together the areas of the two bases, which we learned were 20 as well as the back of the shape and the other three faces facing towards us.
bases back faces
v v
(20 x 2) + (10 x 7) + (4 x 7) + (3 x 7) + (3 x 7) = 40 + 70 +28 + 21 + 21
Add these together to find your surface area of 180 cm^2