Question

there was a total of 750 and 2015 crickets in a pond, the population increased by 17% the next year. The year after that the population decreased by 10%. what is the percent of change of population from the 2015 to 2017?​

Answer 1

Hello there!

In this question, we're going to need to find the population in 2017, while using the given information.

Answer: 5.3% increase

Lets gather the information we should know from the question.

Key information:

2015 -- Population of 750

Increased by 17% in the next year

Decreased by 10% the next year

With the information above, we can solve the problem.

We know that our starting population for crickets is 750, and it increases by 17% for the next year (2016), so we would multiply 750 by 1.17

`750*1.17=877.5`

Our population in 2016 is 877.5.

Now, we know that he population in 2016 decreased by 10% going into 2017. We would need to find how much of 877.5 is 10%, and then subtract.

`877.5*.10=87.75\\\\877.5-87.75=789.75`

When you're done solving, you should get 789.75

This means that the population of crickets in 2017 is 789.75.

Now, we know that we started with 750 crickets, now we have 789.5 crickets.

We would divide 789.5 by 750.

`789.5/750=1.053`

We would move the decimal place two times to the right, giving us 5.3.

This means that the population increased by 5.3% from 2015 to 2017.

I hope this helps!

Best regards, MasterInvestor.

Answer 2

5.2% increase

Explanation:

In 2015 the total population was 750.

In 2016 the total population was 17% more than in 2015, so 750 x 1.17 = 877.

In 2017 the total population was 10% less than in 2016, so 877 x 0.9 = 789.

Compared to 2015, the population in 2017 was 789/750 = 1.052 or 5.2% greater.

In one step:

((750 x 1.17) x 0.9) / 750 = 5.2%