The ratio of grapefruits to dragonfruits is 3 : 5. If 120 dragonfruits are added, the ratio of grapefruits to dragonfruits will be 1 : 5. How many grapefruits are there?
| |
Grapefruits |
Dragonfruits |
| Before |
3x1 =
3 u |
5x1 =
5 u |
| Change |
|
+ 120 |
| After |
1x3 =
3 u |
5x3 =
15 u |
The number of grapefruits at first and in the end remains unchanged. Make the number of grapefruits at first and in the end the same. LCM of 3 and 1 is 3.
Number of dragonfruits added
= 15 u - 5 u
= 10 u
10 u = 120
1 u = 120 ÷ 10 = 12
Number of grapefruits
= 3 u
= 3 x 12
= 36
Answer(s): 36
