What does this mean 100 decreased by 77 mean

It just means 100 - 77% which equals to 23%.

Decreased means reduced or basically taking away a percentage of something. In this case it's numbers in math.

Hope this helps!

answer: the answer is (b) amie should have multiplied

step-by-step explanation: given a sphere and a cylinder with same radius and height.

let, 'r' be the radius of the cylinder and sphere and 'h' be the height of the cylinder. according to the question,

r = h.

now, the volume of the sphere will be

and the volume of the cylinder will be

therefore, we have

thus, ammie should have multiplied the volume of the sphere