The average number of pages Jen read in a certain number of days was 20. In the next eight days, Jen read another 31 pages. As a result, the average number of pages she read decreased to 17. How many days did Jen read in total?
| |
At first |
In the end |
| Number |
1 u |
1 u + 8 |
| Value |
20 |
17 |
| Number x value |
20 u |
17 u + 136 |
Number of days that Jen read at first = 1 u
Number of pages that Jen read at first
= 1 u x 20
= 20 u
Number of pages that Jen read in the end = 20 u + 31
Number of days that Jen read in the end = 1 u + 8
Number of pages that Jen read in the end
= 17 x (1 u + 8)
= 17 u + 136
20 u + 31 = 17 u + 136
20 u - 17 u = 136 - 31
3 u = 105
1 u = 105 ÷ 3 = 35
Number of days that Jen read in the end
= 1 u + 8
= 35 + 8
= 43
Answer(s): 43
