A book shop sold
15 of the books in the morning.
15 of the remaining books are sold in the afternoon. The shop owner brought in another 56 books and there were 2 more books than there were at first. How many books were there in the shop at first?
Morning books sold |
Remaining books |
Brought-in books |
Total books |
1x5 = 5 u |
4x5 = 20 u |
|
5x5 = 25 u |
|
Afternoon books sold
|
Left books
|
|
|
|
1x4 |
4x4 |
|
|
5 u |
4 u |
16 u |
56 |
25 u + 56 |
The remaining number of books is repeated. Make the number of remaining books the same. LCM of 4 and 5 is 20.
Total number of books at first = 25 u
Total number of books in the end = 16 u + 56
Number of books left was 2 more than the number of books at first.
25 u + 2 = 16 u + 56
25 u - 16 u = 56 - 2
9 u = 54
1 u = 54 ÷ 9 = 6
Number of books at first
= 25 u
= 25 x 6
= 150
Answer(s): 150