In a shop, the number of cartons of dragonfruit juice sold was
12 the number of cartons left. When 87 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 left?
|
Sold |
Left |
Total |
Before |
1x7 = 7 u |
2x7 = 14 u |
3x7 = 21 u
|
Change |
+ 87 |
- 87 |
|
After |
7 u + 87 |
14 u - 87 |
21 u |
Comparing the total number of cartons sold and the total number of cartons at first |
4x3 - 3 = 12 u - 3 |
|
7x3 = 21 u |
The total number of cartons is repeated. Make the total number of cartons the same. LCM of 3 and 7 is 21.
The number of cartons sold in the end is repeated.
12 u - 3 = 7 u + 87
12 u - 7 u = 87 + 3
5 u = 90
1 u = 90 ÷ 5 = 18
Number of cartons left
= 14 u - 87
= 14 x 18 - 87
= 252 - 87
= 165
Answer(s): 165