The ratio of pears to grapefruits is 5 : 7. If 69 grapefruits are added, the ratio of pears to grapefruits will be 1 : 6. How many pears are there?
|
Pears |
Grapefruits |
Before |
5x1 = 5 u |
7x1 = 7 u |
Change |
|
+ 69 |
After |
1x5 = 5 u |
6x5 = 30 u |
The number of pears at first and in the end remains unchanged. Make the number of pears at first and in the end the same. LCM of 5 and 1 is 5.
Number of grapefruits added
= 30 u - 7 u
= 23 u
23 u = 69
1 u = 69 ÷ 23 = 3
Number of pears
= 5 u
= 5 x 3
= 15
Answer(s): 15