The average number of pages Nicole read in a certain number of days was 12. In the next five days, Nicole read another 39 pages. As a result, the average number of pages she read decreased to 9. How many days did Nicole read in total?
| |
At first |
In the end |
| Number |
1 u |
1 u + 5 |
| Value |
12 |
9 |
| Number x value |
12 u |
9 u + 45 |
Number of days that Nicole read at first = 1 u
Number of pages that Nicole read at first
= 1 u x 12
= 12 u
Number of pages that Nicole read in the end = 12 u + 39
Number of days that Nicole read in the end = 1 u + 5
Number of pages that Nicole read in the end
= 9 x (1 u + 5)
= 9 u + 45
12 u + 39 = 9 u + 45
12 u - 9 u = 45 - 39
3 u = 6
1 u = 6 ÷ 3 = 2
Number of days that Nicole read in the end
= 1 u + 5
= 2 + 5
= 7
Answer(s): 7
