At the farm, the goose population increased by 20% in the second month and then by a further 15% in the next 7 months. If there were 690 geese in the end, how many geese were there at the farm at first?
|
Geese |
Before |
100% |
Change 1 |
+ 20% |
After 1 |
120% |
Change 2 |
+ 18% |
After 2 |
138% |
Population of geese at first = 100%
New population of geese after first increase
= 100% + 20%
= 120%
Percentage of second increase
= 15% x 120%
=
15100 x 120%
= 18%
New population of geese after second increase
= 120% + 18%
= 138%
138% of goose population = 690
1% of the goose population
= 690 ÷ 138
= 5
100% of goose population
= 100 x 5
= 500
Number of geese at first = 500
Answer(s): 500