The average number of pages Barbara read in a certain number of days was 12. In the next three days, Barbara read another 96 pages. As a result, the average number of pages she read increased to 16. How many days did Barbara read in total?
|
At first |
In the end |
Number |
1 u |
1 u + 3 |
Value |
12 |
16 |
Number x value |
12 u |
16 u + 48 |
Number of days that Barbara read at first = 1 u
Number of pages that Barbara read at first
= 1 u x 12
= 12 u
Number of pages that Barbara read in the end = 12 u + 96
Number of days that Barbara read in the end = 1 u + 3
Number of pages that Barbara read in the end
= 16 x (1 u + 3)
= 16 u + 48
16 u + 48 = 12 u + 96
16 u - 12 u = 96 - 48
4 u = 48
1 u = 48 ÷ 4 = 12
Number of days that Barbara read in the end
= 1 u + 3
= 12 + 3
= 15
Answer(s): 15