At the farm, the cow population increased by 10% in the second month and then by a further 20% in the next 8 months. If there were 528 cows in the end, how many cows were there at the farm at first?
|
Cows |
Before |
100% |
Change 1 |
+ 10% |
After 1 |
110% |
Change 2 |
+ 22% |
After 2 |
132% |
Population of cows at first = 100%
New population of cows after first increase
= 100% + 10%
= 110%
Percentage of second increase
= 20% x 110%
=
20100 x 110%
= 22%
New population of cows after second increase
= 110% + 22%
= 132%
132% of cow population = 528
1% of the cow population
= 528 ÷ 132
= 4
100% of cow population
= 100 x 4
= 400
Number of cows at first = 400
Answer(s): 400