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 Jan to Feb?
2. There were 160 less foolscaps sold in Jan than in Mar. How many foolscaps were sold in Jan?
3. The average number of foolscaps sold from Jan to May was 192. What was the average number of foolscaps sold in Apr and May?

(a)
Percentage increase in the number of foolscaps from Jan to Feb
= ^{5 - 2}₂ x 100%
= ³₂ x 100%
= 150%

(b)
Difference in intervals between Mar and Jan
= 10 - 2
= 8

8 intervals → 160

1 interval → 160 ÷ 8 = 20

Number of foolscaps sold in Jan
= 2 intervals
= 2 x 20
= 40

(c)
Total intervals from Jan to Mar
= 2 + 5 + 10
= 17

Total number of foolscaps sold from Jan to Mar
= 17 intervals
= 17 x 20
= 340

Total number of foolscaps sold from Jan to May
= 5 x 192
= 960

Number of foolscaps sold from Apr to May
= 960 - 340
= 620

Average number of foolscaps sold in Apr and May
= 620 ÷ 2
= 310

Answer(s): (a) 150%; (b) 40; (c) 310