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

1. What was the percentage decrease in the number of pens sold from Feb to Mar?
2. There were 112 more pens sold in Mar than in Jan. How many pens were sold in Feb?
3. The average number of pens sold from Jan to May was 176. What was the average number of pens sold in Apr and May?

(a)
Percentage decrease in the number of pens 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 → 112

1 interval → 112 ÷ 7 = 16

Number of pens sold in Feb
= 10 intervals
= 10 x 16
= 160

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

Total number of pens sold from Jan to Mar
= 19 intervals
= 19 x 16
= 304

Total number of pens sold from Jan to May
= 5 x 176
= 880

Number of pens sold from Apr to May
= 880 - 304
= 576

Average number of pens sold in Apr and May
= 576 ÷ 2
= 288

Answer(s): (a) 20%; (b) 160; (c) 288