In a shop, the number of cartons of pear juice sold was
13 the number of cartons left. When 79 more cartons were sold, the total number of cartons sold was 11 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 |
+ 79 |
- 79 |
|
| After |
7 u + 79 |
21 u - 79 |
28 u |
Comparing the total
number of cartons
sold and the total number of cartons at first |
4x4 - 11 =
16 u - 11 |
|
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 - 11 = 7 u + 79
16 u - 7 u = 79 + 11
9 u = 90
1 u = 90 ÷ 9 = 10
Number of cartons left
= 21 u - 79
= 21 x 10 - 79
= 210 - 79
= 131
Answer(s): 131
