PSLE The bar graph shows the number of pens sold from Jul to Sep. The number of pens sold is not shown on the scale.
- What was the percentage decrease in the number of pens sold from Jul to Aug?
- There were 64 more pens sold in Sep than in Jul. How many pens were sold in Sep?
- The average number of pens sold from Jul to Nov was 148. What was the average number of pens sold in Oct and Nov?
(a)
Percentage decrease in the number of pens from Jul to Aug
=
5 - 35 x 100%
=
25 x 100%
= 40%
(b)
Difference in the number of intervals between Sep and Jul
= 9 - 5
= 4
4 intervals → 64
1 interval → 64 ÷ 4 = 16
Number of pens sold in Sep
= 9 intervals
= 9 x 16
= 144
(c)
Total intervals from Jul to Sep
= 5 + 3 + 9
= 17
Total number of pens sold from Jul to Sep
= 17 intervals
= 17 x 16
= 272
Total number of pens sold from Jul to Nov
= 5 x 148
= 740
Number of pens sold from Oct to Nov
= 740 - 272
= 468
Average number of pens sold in Oct and Nov
= 468 ÷ 2
= 234
Answer(s): (a) 40%; (b) 144; (c) 234