A farmer in Guyana is designing a rectangular pen for chickens using 40 metres of fencing. One side of the pen is against an existing wall, so only three sides need fencing. If the width is x metres, the area A is given by A = x(40 - 2x). What width gives the maximum area?

Q: How do I try a free CXC Mathematics question?

Just tap any of the four options on this page — no signup, no card, nothing to install. You'll see the correct answer and a full mark-scheme-style explanation within a second. Each visit shows a fresh randomly-picked question from the live CXC CSEC Mathematics bank, so you can keep refreshing to try different ones before deciding whether to create a free account for daily access.

Q: Is Kramizo really free for CXC Mathematics students?

Yes — completely free. Every student gets 45 questions a day on the free plan, across any board and any subject, with no card required and no trial countdown. Kramizo's optional Pro plan removes the daily cap and adds analytics, but the free plan is genuinely free forever. We make money from the small percentage of students who choose to upgrade — not from selling data or ads.

Q: Are the Mathematics questions aligned to the CXC CSEC syllabus?

Every question is written against the published CXC CSEC Mathematics syllabus and reviewed for accuracy before being added to the bank. We match the command words (state, describe, explain, evaluate), mark allocations, and difficulty tier you'll see on real CXC past papers. Explanations are written in the style of official examiner mark schemes so students learn exactly what marks are being awarded for.

Question

A farmer in Guyana is designing a rectangular pen for chickens using 40 metres of fencing. One side of the pen is against an existing wall, so only three sides need fencing. If the width is x metres, the area A is given by A = x(40 - 2x). What width gives the maximum area?

Accepted Answer

10 m — Award 1 mark for correct answer. Expanding: A = 40x - 2x². Using x = -b/(2a) = -40/(2×-2) = -40/(-4) = 10 m. A results from dividing total fencing by 4. C results from incorrect calculation. D results from dividing total fencing by 2.

Answer

20 m

Answer

10 m

Answer

15 m

Answer

5 m

One real Mathematics question.No signup. 30 seconds.

One real Mathematics question.
No signup. 30 seconds.