The average number of pages Jean read in a certain number of days was 20. In the next four days, Jean read another 20 pages. As a result, the average number of pages she read decreased to 17. How many days did Jean read in total?
|
At first |
In the end |
Number |
1 u |
1 u + 4 |
Value |
20 |
17 |
Number x value |
20 u |
17 u + 68 |
Number of days that Jean read at first = 1 u
Number of pages that Jean read at first
= 1 u x 20
= 20 u
Number of pages that Jean read in the end = 20 u + 20
Number of days that Jean read in the end = 1 u + 4
Number of pages that Jean read in the end
= 17 x (1 u + 4)
= 17 u + 68
20 u + 20 = 17 u + 68
20 u - 17 u = 68 - 20
3 u = 48
1 u = 48 ÷ 3 = 16
Number of days that Jean read in the end
= 1 u + 4
= 16 + 4
= 20
Answer(s): 20