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

1. What was the percentage increase in the number of foolscaps sold from Feb to Mar?
2. There were 51 more foolscaps sold in Jan than in Feb. How many foolscaps were sold in Mar?
3. The average number of foolscaps sold from Jan to May was 135. What was the average number of foolscaps sold in Apr and May?

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

(b)
Difference in intervals between Jan and Feb
= 5 - 2
= 3

3 intervals → 51

1 interval → 51 ÷ 3 = 17

Number of foolscaps sold in Mar
= 8 intervals
= 8 x 17
= 136

(c)
Total intervals from Jan to Mar
= 5 + 2 + 8
= 15

Total number of foolscaps sold from Jan to Mar
= 15 intervals
= 15 x 17
= 255

Total number of foolscaps sold from Jan to May
= 5 x 135
= 675

Number of foolscaps sold from Apr to May
= 675 - 255
= 420

Average number of foolscaps sold in Apr and May
= 420 ÷ 2
= 210

Answer(s): (a) 300%; (b) 136; (c) 210