The average number of pages Kylie read in a certain number of days was 17. In the next eight days, Kylie read another 31 pages. As a result, the average number of pages she read decreased to 12. How many days did Kylie read in total?
| |
At first |
In the end |
| Number |
1 u |
1 u + 8 |
| Value |
17 |
12 |
| Number x value |
17 u |
12 u + 96 |
Number of days that Kylie read at first = 1 u
Number of pages that Kylie read at first
= 1 u x 17
= 17 u
Number of pages that Kylie read in the end = 17 u + 31
Number of days that Kylie read in the end = 1 u + 8
Number of pages that Kylie read in the end
= 12 x (1 u + 8)
= 12 u + 96
17 u + 31 = 12 u + 96
17 u - 12 u = 96 - 31
5 u = 65
1 u = 65 ÷ 5 = 13
Number of days that Kylie read in the end
= 1 u + 8
= 13 + 8
= 21
Answer(s): 21
