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

1. What was the percentage decrease in the number of glues sold from Feb to Mar?
2. There were 105 more glues sold in Mar than in Jan. How many glues were sold in Feb?
3. The average number of glues sold from Jan to May was 137. What was the average number of glues sold in Apr and May?

(a)
Percentage decrease in the number of glues 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 glues sold in Feb
= 10 intervals
= 10 x 15
= 150

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

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

Total number of glues sold from Jan to May
= 5 x 137
= 685

Number of glues sold from Apr to May
= 685 - 285
= 400

Average number of glues sold in Apr and May
= 400 ÷ 2
= 200

Answer(s): (a) 20%; (b) 150; (c) 200