The average number of pages Shannon read in a certain number of days was 18. In the next seven days, Shannon read another 10 pages. As a result, the average number of pages she read decreased to 16. How many days did Shannon read in total?
|
At first |
In the end |
Number |
1 u |
1 u + 7 |
Value |
18 |
16 |
Number x value |
18 u |
16 u + 112 |
Number of days that Shannon read at first = 1 u
Number of pages that Shannon read at first
= 1 u x 18
= 18 u
Number of pages that Shannon read in the end = 18 u + 10
Number of days that Shannon read in the end = 1 u + 7
Number of pages that Shannon read in the end
= 16 x (1 u + 7)
= 16 u + 112
18 u + 10 = 16 u + 112
18 u - 16 u = 112 - 10
2 u = 102
1 u = 102 ÷ 2 = 51
Number of days that Shannon read in the end
= 1 u + 7
= 51 + 7
= 58
Answer(s): 58