In a shop, the number of cartons of starfruit juice sold was
13 the number of cartons left. When 68 more cartons were sold, the total number of cartons sold was 4 less than
47 the number of cartons the shop had at first. How many cartons were left?
|
Sold |
Left |
Total |
Before |
1x7 = 7 u |
3x7 = 21 u |
4x7 = 28 u
|
Change |
+ 68 |
- 68 |
|
After |
7 u + 68 |
21 u - 68 |
28 u |
Comparing the total number of cartons sold and the total number of cartons at first |
4x4 - 4 = 16 u - 4 |
|
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 - 4 = 7 u + 68
16 u - 7 u = 68 + 4
9 u = 72
1 u = 72 ÷ 9 = 8
Number of cartons left
= 21 u - 68
= 21 x 8 - 68
= 168 - 68
= 100
Answer(s): 100