A fruit seller sells only dragonfruits and mangosteens. The ratio of dragonfruits to mangosteens is 1 : 3. A total of 60 fruits are added. The number of dragonfruits becomes 4 times as many as before and the number of mangosteens becomes 2 times as many as before. How many fruits are there at first?
|
Comparing dragonfruits at first and in the end |
Dragonfruits |
Mangosteens |
Comparing mangosteens at first and in the end |
Before |
1x1 = 1 u |
1 u |
3 u |
1x3 = 3 u |
Change |
|
+ 60 |
|
After |
4x1 = 4 u |
4 u |
6 u |
2x3 = 6 u |
The number of mangosteens at first is repeated. Make the number of mangosteens at first the same. LCM of 1 and 3 is 3.
The number of dragonfruits at first is repeated. Make the number of dragonfruits at first the same. LCM of 1 and 1 is 1.
Number of fruits at first
= 1 u + 3 u
= 4 u
Number of fruits in the end
= 4 u + 6 u
= 10 u
Number of fruits added
= 10 u - 4 u
= 6 u
6 u = 60
1 u = 60 ÷ 6 = 10
Number of fruits at first
= 4 u
= 4 x 10
= 40
Answer(s): 40