A drink stall had 91 big and small packets of soy milk. The number of big packets is
310 of the number of small packets. After selling a few small packets of soy milk, there are
13 as many big packets as small packets left. How many small packets of soy milk were sold?
| |
Big packets |
Small packets |
Total |
| Before |
3 u |
10 u |
13 u |
| Change |
|
- 1 u |
|
| After |
1x3 =
3 u |
3x3 =
9 u |
|
The number of big packets remains unchanged. Make the number of big packets the same. LCM of 3 and 1 is 3.
Number of big packets at first = 3 u
Number of small packets at first = 10 u
Total number of packets at first
= 3 u + 10 u
= 13 u
13 u = 91
1 u = 91 ÷ 13 = 7
Number of small packets sold
= 10 u - 9 u
= 1 u
= 7
Answer(s): 7
