On Friday, Beth will most likely do 39 sit ups. Every day she is doing an extra 6 sit ups.... Thursday would be 33 sit ups and Friday would be 39 sit ups.
The answer is 17/5. First you multiply 5*3=15 then you add 2 which your answer is 17/5.
216 cubes. For the base, you would need 6 x 6 cubes which is 36. Since it is a cube, the height is also 6 so you multiply 36 by 6, which is 216.