The average number of pages Linda read in a certain number of days was 20. In the next eight days, Linda read another 36 pages. As a result, the average number of pages she read decreased to 16. How many days did Linda read in total?
| |
At first |
In the end |
| Number |
1 u |
1 u + 8 |
| Value |
20 |
16 |
| Number x value |
20 u |
16 u + 128 |
Number of days that Linda read at first = 1 u
Number of pages that Linda read at first
= 1 u x 20
= 20 u
Number of pages that Linda read in the end = 20 u + 36
Number of days that Linda read in the end = 1 u + 8
Number of pages that Linda read in the end
= 16 x (1 u + 8)
= 16 u + 128
20 u + 36 = 16 u + 128
20 u - 16 u = 128 - 36
4 u = 92
1 u = 92 ÷ 4 = 23
Number of days that Linda read in the end
= 1 u + 8
= 23 + 8
= 31
Answer(s): 31
