Algebra 1 : How to find the percent of increase

Study concepts, example questions & explanations for Algebra 1

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Example Questions

Example Question #2871 : Algebra 1

Find the percent increase form  to 

Possible Answers:

Correct answer:

Explanation:

For this type of problem we use this formula: 

 

"Difference" is simply the difference between the two numbers given, and "original" is the number that is stated usually after the word "from" , example: from ____ to ____. In this problem our formula will be filled in as follows: 

 

This our percent increase. 

Example Question #81 : Percent Of Change

The cost of gasoline last week was  a gallon.  This week, the cost of gasoline is .  Find the percent of increase.

Possible Answers:

Correct answer:

Explanation:

To find a percentage increase, use the following formula:


 

By substituting, we get

 

 

 

 

 

Example Question #83 : Percent Of Change

Bob took out a personal loan from the bank in the amount of . One month later, Bob's bank sent him a billing statement, totalling the debt at . By what percent did Bob's debt to the bank increase?

Possible Answers:

Correct answer:

Explanation:

To find the percent increase, we want to first divide the total increase by the initial cash amount:

Next we multiply the given value by :

Example Question #84 : Percent Of Change

Henry grows his own produce in a garden. Last week Henry harvested  of carrots and this week harvested  of carrots. By what percent did Henry's yield of carrots increase within the week?

Possible Answers:

Correct answer:

Explanation:

To determine the percent increase, we must determine the difference between the 2 values and divide them by the initial yield:

Example Question #85 : Percent Of Change

A certain town has seen a recent increase in population, growing from  residents in 1990 to  today. By what percent has the population increased since 1990?

Possible Answers:

Correct answer:

Explanation:

To find the percent of increase, we want to divide the number of new residents by the original population and multiply that decimal value by :

Example Question #85 : Percent Of Change

Sally currently makes $90000 per year as an engineer. After several years working for her engineering firm, Sally's supervisor notices superior quality of Sally's work, and decides to raise her annual salary to $112500. By what percentage did Sally's salary increase?

Possible Answers:

Correct answer:

Explanation:

The general formula for calculating percent change is 

In our case, the new (value) is Sally's new salary and the original (value) is her old salary. Plug these values into our equation and simplify.

Example Question #81 : How To Find The Percent Of Increase

Last week, gasoline cost $2.50 a gallon. This week, gasoline costs $2.75 a gallon. Find the percent increase rounded to the nearest percent.

Possible Answers:

Correct answer:

Explanation:

To find percent increase, we use the formula

So, we can substitute our values into the formula.  We get

Therefore, the percent increase is 

Example Question #82 : How To Find The Percent Of Increase

Last week, you bought cheese for $2 a pound.  This week, you bought it for $3.50 a pound.  Find the percent increase.  Round to the nearest percent.

Possible Answers:

1.5%

75%

80%

50%

2%

Correct answer:

75%

Explanation:

To find the percent of increase, we use the following formula:

The original price is $2.  The new price is $3.50.  So we can substitute.  We get

Therefore, the percent increase is 75%.

Example Question #2872 : Algebra 1

If the field botany course offered by a local university increases its enrollment from 18 students to 27 students, what is the percent increase in the number of students?

Possible Answers:

Correct answer:

Explanation:

If the field botany course offered by a local university increases its enrollment from 18 students to 27 students, what is the percent increase in the number of students?

 

To find the percent increase, we need to divide the difference by the original number.

So, find the difference:

 

and divide by the original

Not that it is NOT  increase, that would be mean the new enrollment is 45 students:

Example Question #88 : Percent Of Change

If the number of Republican voters in a certain district has decreased from 150,000 to 78,560, what is the percent decrease in the number of Republican voters?

Possible Answers:

Correct answer:

Explanation:

If the number of Republican voters in a certain district has decreased from 150,000 to 78,560, what is the percent decrease in the number of Republican voters?

 

To find the percent of decrease, we need to divide the difference by the original number:

So the number of Republican voters decreased by about 

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