Seven hours ago, a store owner started his day with some oranges and apples in the ratio of 7 : 3. There were 36 apples. Some of the oranges were bought by Xuan. As a result, the number of oranges became
34 of the apples.
- How many oranges did the store owner have left?
- How many oranges did the store owner have to buy in order to have an equal number of oranges and apples?
|
Oranges |
Apples |
Before |
7x4 = 28 u |
3x4 = 12 u |
Change |
- ? |
|
After |
3x3 = 9 u |
4x3 = 12 u |
(a)
The number of apples remains unchanged. Make the number of apples the same. LCM of 3 and 4 is 12.
12 u = 36
1 u = 36 ÷ 12 = 3
Number of oranges that the store owner had left
= 9 u
= 9 x 3
= 27
(b)
Number of oranges that the store owner had to buy to have an equal number of oranges and apples
= 12 u - 9 u
= 3 u
= 3 x 3
= 9
Answer(s): (a) 27; (b) 9