John had dragonfruits and starfruits. The ratio of dragonfruits to starfruits was 9 : 2. After
45 of the dragonfruits and 81 starfruits were sold, there were 9 times as many dragonfruits as starfruits left. How many dragonfruits and starfruits were there at first?
| |
Dragonfruits |
Starfruits |
Comparing dragonfruits
and starfruits at first |
9x5 =
45 u |
2x5 =
10 u |
| Before |
5x9 =
45 u |
|
| Change |
- 4x9 =
- 36 u |
- 81 |
| After |
1x9 =
9 u |
|
Comparing dragonfruits
and starfruits in the end |
9 u |
1 u |
The number of dragonfruits at first is repeated. Make the number of dragonfruits at first the same. LCM of 9 and 5 is 45.
Number of starfruits sold
= 10 u - 1 u
= 9 u
9 u = 81
1 u = 81 ÷ 9 = 9
Number of dragonfruits and starfruits at first
= 45 u + 10 u
= 55 u
= 55 x 9
= 495
Answer(s): 495
