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

1. What was the percentage increase in the number of correction tapes sold from Feb to Mar?
2. There were 42 more correction tapes sold in Jan than in Feb. How many correction tapes were sold in Mar?
3. The average number of correction tapes sold from Jan to May was 128. What was the average number of correction tapes sold in Apr and May?

(a)
Percentage increase in the number of correction tapes 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 → 42

1 interval → 42 ÷ 3 = 14

Number of correction tapes sold in Mar
= 8 intervals
= 8 x 14
= 112

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

Total number of correction tapes sold from Jan to Mar
= 15 intervals
= 15 x 14
= 210

Total number of correction tapes sold from Jan to May
= 5 x 128
= 640

Number of correction tapes sold from Apr to May
= 640 - 210
= 430

Average number of correction tapes sold in Apr and May
= 430 ÷ 2
= 215

Answer(s): (a) 300%; (b) 112; (c) 215