At the farm, the duck population increased by 20% in the second month and then by a further 15% in the next 8 months. If there were 828 ducks in the end, how many ducks were there at the farm at first?
| |
Ducks |
| Before |
100% |
| Change 1 |
+ 20% |
| After 1 |
120% |
| Change 2 |
+ 18% |
| After 2 |
138% |
Population of ducks at first = 100%
New population of ducks after first increase
= 100% + 20%
= 120%
Percentage of second increase
= 15% x 120%
=
15100 x 120%
= 18%
New population of ducks after second increase
= 120% + 18%
= 138%
138% of duck population = 828
1% of the duck population
= 828 ÷ 138
= 6
100% of duck population
= 100 x 6
= 600
Number of ducks at first = 600
Answer(s): 600
