Criticise the solution

[Guest]

So essentially I am having trouble understanding the meaning of this question, normally my math isn't bad but this is confusing me. Any assistance would be appreciated haha.

Question

A landscape gardener has been asked to design and turf a lawn for a new house.
They have created two different designs: designs 1 is a trapezium-shaped lawn,
which would have parallel sides of 4m and 7m, and a width of 6m; and design 2
is a circular lawn, which would have a diameter of 7m. The gardener can buy turf
for £5 per metre squared. How much will the turf cost for each lawn design in pounds
and pence? Which lawn design is the most expensive to turf?

Solution

0.5 * (4+7) * 6 * 5 = 165.

3.5^2 * [tex]\pi[/tex] * 5 = 192.4

(a) Criticise the solution, explaining why it would be difficult to follow.

(b) Write out a better solution.

[Guest]

I would say that, first, there is no explanation. Second, the final question, "Which lawn design is the most expensive to turf?", is not answered!

I would have done this:
The trapezoid has area 0.5 * (4+7) * 6= 33 square meters. At 5 pounds per square meters that is 33* 5 = 165 pounds.

The circle has area 3.5^2 * π= 38.5 square meters. At 5 pounds per square meter that is 38.5*5= 192.4 pounds.

The second lawn design, the circle, is the more expensive.

(Though the question apparently uses the words "most expensive", since there are only two things "more expensive" is grammatically correct, not "most expensive".)