A departmental store had 180 lamps for sale during a 7-day period. The line graph shows the number of lamps left unsold at the end of each day. The number of lamps left unsold at the end of Day 7 was not shown.
- On which day was the greatest number of lamps sold? Give your answer in number. (Eg 1)
- The average number of lamps sold for the last three days was 12. How many lamps were sold on Day 7?
(a)
To find the greatest increase in the number of tickets sold, look for the steepest decreasing slope.
On Day 1, the number of lamps sold was the greatest number.
(b)
Total number of lamps sold on the last three days
= 3 x 12
= 36
Total number of lamps sold on Day 5 and Day 6
= 25 + 10
= 35
Total number of lamps sold on Day 7
= 36 - 35
= 1
Answer(s): (a) 1; (b) 1