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

1. What was the percentage increase in the number of folders sold from Jan to Feb?
2. There were 96 less folders sold in Jan than in Mar. How many folders were sold in Jan?
3. The average number of folders sold from Jan to May was 130. What was the average number of folders sold in Apr and May?

(a)
Percentage increase in the number of folders 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 → 96

1 interval → 96 ÷ 8 = 12

Number of folders sold in Jan
= 2 intervals
= 2 x 12
= 24

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

Total number of folders sold from Jan to Mar
= 17 intervals
= 17 x 12
= 204

Total number of folders sold from Jan to May
= 5 x 130
= 650

Number of folders sold from Apr to May
= 650 - 204
= 446

Average number of folders sold in Apr and May
= 446 ÷ 2
= 223

Answer(s): (a) 150%; (b) 24; (c) 223