Question

Due to over fishing, scientists estimate that fish numbers have dropped by 2400 to 960 in a lake. What has been the percentage decrease?

Answer 1

Decrease is `60%`

Explanation:

Percentage increase / decrease is always calculated by dividing the increase / decrease in quantum to original quantum and then multiplying it by `100`.

As the fish numbers have dropped from `2,400` to `960`

the decline is `2400-960=1440`

This decrease has been from `2,400` and hence

Percentage decrease is `1440/2400xx100`

= `(4xx6xx6xx10)/(4xx6xx10xx10)xx100`

= `(cancel4xxcancel6xx6xxcancel10)/(cancel4xxcancel6xxcancel10xxcancel10)xx10cancel100`

= `6xx10=60`