Andy had grapefruits and mangosteens. The ratio of grapefruits to mangosteens was 9 : 4. After
12 of the grapefruits and 21 mangosteens were sold, there were 9 times as many grapefruits as mangosteens left. How many grapefruits and mangosteens were there at first?
| |
Grapefruits |
Mangosteens |
Comparing grapefruits
and mangosteens at first |
9x2 =
18 u |
4x2 =
8 u |
| Before |
2x9 =
18 u |
|
| Change |
- 1x9 =
- 9 u |
- 21 |
| After |
1x9 =
9 u |
|
Comparing grapefruits
and mangosteens in the end |
9 u |
1 u |
The number of grapefruits at first is repeated. Make the number of grapefruits at first the same. LCM of 9 and 2 is 18.
Number of mangosteens sold
= 8 u - 1 u
= 7 u
7 u = 21
1 u = 21 ÷ 7 = 3
Number of grapefruits and mangosteens at first
= 18 u + 8 u
= 26 u
= 26 x 3
= 78
Answer(s): 78
