Add Math Project 2010 Answer (Worksheet 1)

Further Exploration
(a)(i) Structure 1

(ii) Structure 2

(iii) Structure 3

(iv) Structure 4

Conclusion
Structure 4 will cost the minimum to construct

a(ii)
As the president, I will choose structure 4 so that I can minimize the construction cost.

B(i)

(b)(ii)
Area to be painted
3, 2.9375, 2.875, ......., 2.5
This is an Arithmetic Progression (AP) with
common difference, d = 2.9375 - 3 = -0.0625 (or 2.875 - 2.9375 = -0.0625)
When k increases by 0.25m, the area to be painted decreases by 0.0625 m

(c)

When

The shape of the concrete is a rectangle with length 4m and breadth 0.5m.