In a shop, the number of cartons of grapefruit juice sold was
13 the number of cartons left. When 85 more cartons were sold, the total number of cartons sold was 5 less than
710 the number of cartons the shop had at first. How many cartons were left?
|
Sold |
Left |
Total |
Before |
1x5 = 5 u |
3x5 = 15 u |
4x5 = 20 u
|
Change |
+ 85 |
- 85 |
|
After |
5 u + 85 |
15 u - 85 |
20 u |
Comparing the total number of cartons sold and the total number of cartons at first |
7x2 - 5 = 14 u - 5 |
|
10x2 = 20 u |
The total number of cartons is repeated. Make the total number of cartons the same. LCM of 4 and 10 is 20.
The number of cartons sold in the end is repeated.
14 u - 5 = 5 u + 85
14 u - 5 u = 85 + 5
9 u = 90
1 u = 90 ÷ 9 = 10
Number of cartons left
= 15 u - 85
= 15 x 10 - 85
= 150 - 85
= 65
Answer(s): 65