At the farm, the duck population increased by 20% in the second month and then by a further 10% in the next 5 months. If there were 660 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 |
+ 12% |
After 2 |
132% |
Population of ducks at first = 100%
New population of ducks after first increase
= 100% + 20%
= 120%
Percentage of second increase
= 10% x 120%
=
10100 x 120%
= 12%
New population of ducks after second increase
= 120% + 12%
= 132%
132% of duck population = 660
1% of the duck population
= 660 ÷ 132
= 5
100% of duck population
= 100 x 5
= 500
Number of ducks at first = 500
Answer(s): 500