The average number of pages Penelope read in a certain number of days was 12. In the next three days, Penelope read another 26 pages. As a result, the average number of pages she read decreased to 10. How many days did Penelope read in total?
| |
At first |
In the end |
| Number |
1 u |
1 u + 3 |
| Value |
12 |
10 |
| Number x value |
12 u |
10 u + 30 |
Number of days that Penelope read at first = 1 u
Number of pages that Penelope read at first
= 1 u x 12
= 12 u
Number of pages that Penelope read in the end = 12 u + 26
Number of days that Penelope read in the end = 1 u + 3
Number of pages that Penelope read in the end
= 10 x (1 u + 3)
= 10 u + 30
12 u + 26 = 10 u + 30
12 u - 10 u = 30 - 26
2 u = 4
1 u = 4 ÷ 2 = 2
Number of days that Penelope read in the end
= 1 u + 3
= 2 + 3
= 5
Answer(s): 5
