The average number of pages Sabrina read in a certain number of days was 20. In the next five days, Sabrina read another 46 pages. As a result, the average number of pages she read decreased to 18. How many days did Sabrina read in total?
|
At first |
In the end |
Number |
1 u |
1 u + 5 |
Value |
20 |
18 |
Number x value |
20 u |
18 u + 90 |
Number of days that Sabrina read at first = 1 u
Number of pages that Sabrina read at first
= 1 u x 20
= 20 u
Number of pages that Sabrina read in the end = 20 u + 46
Number of days that Sabrina read in the end = 1 u + 5
Number of pages that Sabrina read in the end
= 18 x (1 u + 5)
= 18 u + 90
20 u + 46 = 18 u + 90
20 u - 18 u = 90 - 46
2 u = 44
1 u = 44 ÷ 2 = 22
Number of days that Sabrina read in the end
= 1 u + 5
= 22 + 5
= 27
Answer(s): 27