Two hours ago, a stallholder started his day with some starfruits and lemons in the ratio of 5 : 4. There were 180 lemons. Some of the starfruits were bought by Shiyun. As a result, the number of starfruits became
25 of the lemons.
- How many starfruits did the stallholder have left?
- How many starfruits did the stallholder have to buy in order to have an equal number of starfruits and lemons?
|
Starfruits |
Lemons |
Before |
5x5 = 25 u |
4x5 = 20 u |
Change |
- ? |
|
After |
2x4 = 8 u |
5x4 = 20 u |
(a)
The number of lemons remains unchanged. Make the number of lemons the same. LCM of 4 and 5 is 20.
20 u = 180
1 u = 180 ÷ 20 = 9
Number of starfruits that the stallholder had left
= 8 u
= 8 x 9
= 72
(b)
Number of starfruits that the stallholder had to buy to have an equal number of starfruits and lemons
= 20 u - 8 u
= 12 u
= 12 x 9
= 108
Answer(s): (a) 72; (b) 108