2008 - JAMB Mathematics Past Questions and Answers - page 10

Area of semicircle + Area of rectangle

A = \(\frac{1}{2} \pi r^2\) + LB

A = \(\frac{1}{2} \times \frac{22}{77} \times (\frac{5}{2})^2 + (15 \times 5)\)

= \(\frac{1}{2}\times \frac{22}{7} \times \frac{25}{4} + 75\)

A = \(\frac{275}{28} + \frac{75}{1}\)

\(\frac{275 + 2100}{28} = \frac{2375}{28}\)

A = 84.8cm²

\(\frac{\text{least}}{\text{most}} = \frac{3}{12} = \frac{1}{4}\)