Algebra 1 is a high school course. You learn some of the same things but in algebra it's more complicated.
Answer: Choice D
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Explanation:
The formula for the surface area of a cylinder is

We then replace r with 10 and h with 25. Keep in mind that the diameter is 20 mm, so the radius is half that at 10 mm.
So that's how we get to

Mark received £ 132
<em><u>Solution:</u></em>
Given that £440 is divided between David, Mark & Henry
Let "d" be the share of david
Let "m" be the share of mark
Let "h" be the share of henry
Total amount is 440
Therefore,
share of david + share of mark + share of henry = 440
d + m + h = 440 ------- eqn 1
<em><u>David gets twice as much as Mark</u></em>
d = 2m ----- eqn 2
<em><u>Mark gets three times as much as Henry</u></em>
m = 3h
------ eqn 3
<em><u>Substitute eqn 2 and eqn 3 in eqn 1</u></em>

Thus Mark received £ 132
Yes you can simplify an improper fraction