The average number of pages Fanny read in a certain number of days was 17. In the next five days, Fanny read another 11 pages. As a result, the average number of pages she read decreased to 15. How many days did Fanny read in total?
| |
At first |
In the end |
| Number |
1 u |
1 u + 5 |
| Value |
17 |
15 |
| Number x value |
17 u |
15 u + 75 |
Number of days that Fanny read at first = 1 u
Number of pages that Fanny read at first
= 1 u x 17
= 17 u
Number of pages that Fanny read in the end = 17 u + 11
Number of days that Fanny read in the end = 1 u + 5
Number of pages that Fanny read in the end
= 15 x (1 u + 5)
= 15 u + 75
17 u + 11 = 15 u + 75
17 u - 15 u = 75 - 11
2 u = 64
1 u = 64 ÷ 2 = 32
Number of days that Fanny read in the end
= 1 u + 5
= 32 + 5
= 37
Answer(s): 37
