WAEC 2011 · Paper 2 · Q5

A library received a $1,300 grant. It spends 10%10\% of the grant on magazine subscriptions, 35%35\% on new books, 15%15\% to repair damaged books, 30%30\% to buy new furniture and 10%10\% to train library staff.

  1. (a)

    Represent this information on a pie chart.

    Separate values with commas, e.g. 3, −2

  2. (b)

    Calculate, correct to the nearest whole number, the percentage increase of the amount for buying new books over that of new furniture.

Worked solution (try it first)

(a)

  1. The whole circle, 360∘360^\circ, stands for the whole grant, 100%100\%.
  2. So each 1%1\% is 3.6∘3.6^\circ: magazines 10×3.6∘=36∘10 \times 3.6^\circ = 36^\circ, new books 35×3.6∘=126∘35 \times 3.6^\circ = 126^\circ, repairs 54∘54^\circ, furniture 108∘108^\circ and training 36∘36^\circ.
  3. Check: 36+126+54+108+36=36036 + 126 + 54 + 108 + 36 = 360.
  4. Draw a circle with compasses, draw one radius as a starting line, then measure each angle in turn with a protractor.
  5. Label each sector with the item and its angle.

(b)

  1. New books get 35%35\% of $1,300, which is $455.
  2. Furniture gets 30%30\%, which is $390.
  3. The increase is $65, so the percentage increase over furniture is 65390×100≈16.7%\frac{65}{390} \times 100 \approx 16.7\%, which is 17%17\% to the nearest whole number.
  4. (Straight from the percentages: 35−3030×100\frac{35 - 30}{30} \times 100 gives the same.)

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