Need help with maths question

how many marks are each part?

Below I have attached 2 questions that I need help with, I would appreciate it if you can show how to work the question out so I can understand how to answer the question.

The answer to the first one is 185 litres
The answer to the second one is 11160 cm^3 (to 4 s.f.)

I’m just gonna give you the gist of it. So you wanna utilise the property of similar shapes. So label the total height as h. We got a ratio of 80:60, which simplifies to 4:3. We can see we get two pyramids right. One has the length and width of 80 and 100, whilst the second has a length of 60 and 75 (as base). Now the 80x100 pyramid has a height of h. The 60x75 has a height of h-30 (since the frustum height is 30, we minus it from h. Now by utilising the ratio, h:h-30 = 4:3. This means, after some rearrangement, 4(h-30) = 3h. Rearrange to get h = 120. That’s our height. Now use the formula for volume of a pyramid to find the two pyramids and subtract. This same idea is in the second question. Since one circle is larger than the other, we can assume a cone has been cut. So use the idea of similar shape in that! Hope this helps