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

1. What was the percentage increase in the number of pencils sold from Feb to Mar?
2. There were 39 more pencils sold in Jan than in Feb. How many pencils were sold in Mar?
3. The average number of pencils sold from Jan to May was 105. What was the average number of pencils sold in Apr and May?

(a)
Percentage increase in the number of pencils 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 → 39

1 interval → 39 ÷ 3 = 13

Number of pencils sold in Mar
= 8 intervals
= 8 x 13
= 104

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

Total number of pencils sold from Jan to Mar
= 15 intervals
= 15 x 13
= 195

Total number of pencils sold from Jan to May
= 5 x 105
= 525

Number of pencils sold from Apr to May
= 525 - 195
= 330

Average number of pencils sold in Apr and May
= 330 ÷ 2
= 165

Answer(s): (a) 300%; (b) 104; (c) 165