The average number of pages Ivory read in a certain number of days was 14. In the next four days, Ivory read another 82 pages. As a result, the average number of pages she read increased to 16. How many days did Ivory read in total?
|
At first |
In the end |
Number |
1 u |
1 u + 4 |
Value |
14 |
16 |
Number x value |
14 u |
16 u + 64 |
Number of days that Ivory read at first = 1 u
Number of pages that Ivory read at first
= 1 u x 14
= 14 u
Number of pages that Ivory read in the end = 14 u + 82
Number of days that Ivory read in the end = 1 u + 4
Number of pages that Ivory read in the end
= 16 x (1 u + 4)
= 16 u + 64
16 u + 64 = 14 u + 82
16 u - 14 u = 82 - 64
2 u = 18
1 u = 18 ÷ 2 = 9
Number of days that Ivory read in the end
= 1 u + 4
= 9 + 4
= 13
Answer(s): 13