The average number of pages Pamela read in a certain number of days was 14. In the next four days, Pamela read another 98 pages. As a result, the average number of pages she read increased to 21. How many days did Pamela read in total?
|
At first |
In the end |
Number |
1 u |
1 u + 4 |
Value |
14 |
21 |
Number x value |
14 u |
21 u + 84 |
Number of days that Pamela read at first = 1 u
Number of pages that Pamela read at first
= 1 u x 14
= 14 u
Number of pages that Pamela read in the end = 14 u + 98
Number of days that Pamela read in the end = 1 u + 4
Number of pages that Pamela read in the end
= 21 x (1 u + 4)
= 21 u + 84
21 u + 84 = 14 u + 98
21 u - 14 u = 98 - 84
7 u = 14
1 u = 14 ÷ 7 = 2
Number of days that Pamela read in the end
= 1 u + 4
= 2 + 4
= 6
Answer(s): 6