In a shop, the number of cartons of pear juice sold was
12 the number of cartons left. When 56 more cartons were sold, the total number of cartons sold was 4 less than
79 the number of cartons the shop had at first. How many cartons were there at first?
| |
Sold |
Left |
Total |
| Before |
1x3 =
3 u |
2x3 =
6 u |
3x3 =
9 u
|
| Change |
+ 56 |
- 56 |
|
| After |
3 u + 56 |
6 u - 56 |
9 u |
Comparing the total number
of cartons sold and the total
number of cartons at first |
7x1 - 4 =
7 u - 4 |
|
9x1 =
9 u |
The total number of cartons is repeated. Make the total number of cartons the same. LCM of 3 and 9 is 9.
The number of cartons sold in the end is repeated.
7 u - 4 = 3 u + 56
7 u - 3 u = 56 + 4
4 u = 60
1 u = 60 ÷ 4 = 15
Number of cartons at first
= 9 u
= 9 x 15
= 135
Answer(s): 135
