WAEC 2013 · Paper 2 · Q2

(a)
Solve: $7x + 4 < \frac12(4x + 3)$ .
Show the answer
$x < -\frac12$
(b)
Salem, Sunday and Shaka shared a sum of ₦1,100.00. For every ₦2.00 that Salem gets, Sunday gets fifty kobo, and for every ₦4.00 Sunday gets, Shaka gets ₦2.00. Find Shaka's share.

Worked solution (try it first)

For every ₦2.00 Salem gets, Sunday gets ₦0.50: Salem : Sunday $= 2 : 0.5 = 4 : 1$ .
For every ₦4.00 Sunday gets, Shaka gets ₦2.00: Sunday : Shaka $= 4 : 2 = 2 : 1$ .
Make Sunday's parts match: $4 : 1 = 8 : 2$ and $2 : 1$ , so Salem : Sunday : Shaka $= 8 : 2 : 1$ (11 parts).
Shaka's share $= \frac{1}{11} \times 1100 = ₦100$ .