(a) Evaluate without using calculator, ((frac{1}{4} times 9frac{1}{7} + frac{2}{5} (frac{2}{2} + frac{3}{4})) div (frac{2}{5} – frac{1}{4}))
(b) A hunter walked 250 m from point P to Q on a bearing 042(^o). Calculate, correct to the nearest meter the vertical distance he has moved.
Explanation
The Chief Examiner reported that in part (a), some Candidates’ carried out the requirement of BODMAS correctly tile few couldn’t. However, in part (b), most Candidates’ could not sketch the diagram correctly and hence failed to earn the marks allocated.
In part (a), expressing as improper fraction we have ((frac{1}{4} times 9frac{1}{7} + frac{2}{5} (frac{2}{2} + frac{3}{4})) div (frac{2}{5} – frac{1}{4})) Next, using BODMAS to get ((frac{16}{7} + frac{2}{5} times frac{17}{12}) div frac{17}{12}). Simplifying and inverting yields (frac{1198}{420} times frac{20}{3} = 19frac{1}{63})
In part (b), they were expected to sketch
Then, using trigonometric ratio to have sin 48(^o) = (frac{x}{250}) or cos 42(^o) = (frac{x}{250}) and simplifying the vertical distance moved to be 186 m.