PSLE The bar graph shows the number of pencils sold from Jan to Mar. The number of pencils sold is not shown on the scale.
- What was the percentage decrease in the number of pencils sold from Feb to Mar?
- There were 77 more pencils sold in Mar than in Jan. How many pencils were sold in Feb?
- The average number of pencils sold from Jan to May was 149. What was the average number of pencils sold in Apr and May?
(a)
Percentage decrease in the number of pencils from Feb to Mar
=
10 - 810 x 100%
=
210 x 100%
= 20%
(b)
Difference in the number of intervals between Mar and Jan
= 8 - 1
= 7
7 intervals → 77
1 interval → 77 ÷ 7 = 11
Number of pencils sold in Feb
= 10 intervals
= 10 x 11
= 110
(c)
Total intervals from Jan to Mar
= 1 + 10 + 8
= 19
Total number of pencils sold from Jan to Mar
= 19 intervals
= 19 x 11
= 209
Total number of pencils sold from Jan to May
= 5 x 149
= 745
Number of pencils sold from Apr to May
= 745 - 209
= 536
Average number of pencils sold in Apr and May
= 536 ÷ 2
= 268
Answer(s): (a) 20%; (b) 110; (c) 268