In a shop, the number of cartons of lemon juice sold was
13 the number of cartons left. When 51 more cartons were sold, the total number of cartons sold was 3 less than
47 the number of cartons the shop had at first. How many cartons were there at first?
|
Sold |
Left |
Total |
Before |
1x7 = 7 u |
3x7 = 21 u |
4x7 = 28 u
|
Change |
+ 51 |
- 51 |
|
After |
7 u + 51 |
21 u - 51 |
28 u |
Comparing the total number of cartons sold and the total number of cartons at first |
4x4 - 3 = 16 u - 3 |
|
7x4 = 28 u |
The total number of cartons is repeated. Make the total number of cartons the same. LCM of 4 and 7 is 28.
The number of cartons sold in the end is repeated.
16 u - 3 = 7 u + 51
16 u - 7 u = 51 + 3
9 u = 54
1 u = 54 ÷ 9 = 6
Number of cartons at first
= 28 u
= 28 x 6
= 168
Answer(s): 168