PSLE
The bar graph shows the number of foolscaps sold from Jul to Sep. The number of foolscaps sold is not shown on the scale.

1. What was the percentage increase in the number of foolscaps sold from Aug to Sep?
2. There were 30 more foolscaps sold in Jul than in Aug. How many foolscaps were sold in Sep?
3. The average number of foolscaps sold from Jul to Nov was 112. What was the average number of foolscaps sold in Oct and Nov?

(a)
Percentage increase in the number of foolscaps sold from Aug to Sep
= ^{8 - 2}₂ x 100%
= ⁶₂ x 100%
= 300%

(b)
Difference in intervals between Jul and Aug
= 5 - 2
= 3

3 intervals → 30

1 interval → 30 ÷ 3 = 10

Number of foolscaps sold in Sep
= 8 intervals
= 8 x 10
= 80

(c)
Total intervals from Jul to Sep
= 5 + 2 + 8
= 15

Total number of foolscaps sold from Jul to Sep
= 15 intervals
= 15 x 10
= 150

Total number of foolscaps sold from Jul to Nov
= 5 x 112
= 560

Number of foolscaps sold from Oct to Nov
= 560 - 150
= 410

Average number of foolscaps sold in Oct and Nov
= 410 ÷ 2
= 205

Answer(s): (a) 300%; (b) 80; (c) 205