Four hours ago, a grocer started his day with some mangosteens and oranges in the ratio of 7 : 2. There were 90 oranges. Some of the mangosteens were bought by Barbara. As a result, the number of mangosteens became
35 of the oranges.
- How many mangosteens did the grocer have left?
- How many mangosteens did the grocer have to buy in order to have an equal number of mangosteens and oranges?
|
Mangosteens |
Oranges |
Before |
7x5 = 35 u |
2x5 = 10 u |
Change |
- ? |
|
After |
3x2 = 6 u |
5x2 = 10 u |
(a)
The number of oranges remains unchanged. Make the number of oranges the same. LCM of 2 and 5 is 10.
10 u = 90
1 u = 90 ÷ 10 = 9
Number of mangosteens that the grocer had left
= 6 u
= 6 x 9
= 54
(b)
Number of mangosteens that the grocer had to buy to have an equal number of mangosteens and oranges
= 10 u - 6 u
= 4 u
= 4 x 9
= 36
Answer(s): (a) 54; (b) 36