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

1. What was the percentage decrease in the number of staplers sold from Feb to Mar?
2. There were 105 more staplers sold in Mar than in Jan. How many staplers were sold in Feb?
3. The average number of staplers sold from Jan to May was 165. What was the average number of staplers sold in Apr and May?

(a)
Percentage decrease in the number of staplers from Feb to Mar
= ^{10 - 8}₁₀ x 100%
= ²₁₀ x 100%
= 20%

(b)
Difference in the number of intervals between Mar and Jan
= 8 - 1
= 7

7 intervals → 105

1 interval → 105 ÷ 7 = 15

Number of staplers sold in Feb
= 10 intervals
= 10 x 15
= 150

(c)
Total intervals from Jan to Mar
= 1 + 10 + 8
= 19

Total number of staplers sold from Jan to Mar
= 19 intervals
= 19 x 15
= 285

Total number of staplers sold from Jan to May
= 5 x 165
= 825

Number of staplers sold from Apr to May
= 825 - 285
= 540

Average number of staplers sold in Apr and May
= 540 ÷ 2
= 270

Answer(s): (a) 20%; (b) 150; (c) 270