(a) The diagram, = IWYI = IXZI and < WXY = 80\(^o\). What is the size of < XWZ?
(b) A man was charged 2 kobo per month for every N1.00 he borrowed from a bank. At what rate per annum was the interest charged?
Attached Figure / Diagram
Verified Correct Answer: .
Step-by-Step Mathematical Solution
(a) First joining XZ and WY, we have < XWY = < XZY = \(\frac{1}{2}\)(180^\circ — 80^\circ) = 50^\circ. This implies that < ZXY = 50^\circ(base angles of an isosceles triangle). So that < XWZ = 180^\circ - 80^\circ = 100^\circ.
(b) The rate in every N1.00 = \(\frac{2}{100}\) so that the rate of interest charged per annum will be \(\frac{2 \times 12}{100}\) x 100 which gives 24%.
Source: Myschool Past Questions Archive (Record #56162)