The average number of pages Olivia read in a certain number of days was 18. In the next seven days, Olivia read another 50 pages. As a result, the average number of pages she read decreased to 14. How many days did Olivia read in total?
| |
At first |
In the end |
| Number |
1 u |
1 u + 7 |
| Value |
18 |
14 |
| Number x value |
18 u |
14 u + 98 |
Number of days that Olivia read at first = 1 u
Number of pages that Olivia read at first
= 1 u x 18
= 18 u
Number of pages that Olivia read in the end = 18 u + 50
Number of days that Olivia read in the end = 1 u + 7
Number of pages that Olivia read in the end
= 14 x (1 u + 7)
= 14 u + 98
18 u + 50 = 14 u + 98
18 u - 14 u = 98 - 50
4 u = 48
1 u = 48 ÷ 4 = 12
Number of days that Olivia read in the end
= 1 u + 7
= 12 + 7
= 19
Answer(s): 19
