Algebra 1 : Whole and Part

Study concepts, example questions & explanations for Algebra 1

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Example Questions

Example Question #1 : How To Find The Whole From The Part With Percentage

70% of a quantity is 35. What is the quantity?

Possible Answers:

\displaystyle 24.5

\displaystyle 45.5

\displaystyle 50

\displaystyle 42

\displaystyle 44.5

Correct answer:

\displaystyle 50

Explanation:

We can write this as an equation:

\displaystyle 0.70\cdot x=35

\displaystyle x=\frac{35}{0.7}

\displaystyle x=50

Example Question #2 : Whole And Part

80% of ____ = 72?

Possible Answers:

\displaystyle 80

\displaystyle 88

\displaystyle 94

\displaystyle 90

\displaystyle 86

Correct answer:

\displaystyle 90

Explanation:

\displaystyle \frac{80}{100}=\frac{4}{5}

\displaystyle \frac{4}{5}x=72

Divide by fractions:

  \displaystyle x=\frac{5}{4}\cdot 72=90

Example Question #2 : How To Find The Whole From The Part With Percentage

Malcolm spent 15% of his money on a bicycle that costs $300. How many dollars does Malcolm have left?

Possible Answers:

\displaystyle 1700

\displaystyle 1600

\displaystyle 1500

\displaystyle 2000

\displaystyle 1800

Correct answer:

\displaystyle 1700

Explanation:

If $300 was 15% of Malcolm's money, then we can figure out how much money Malcolm had by creating this equation:

\displaystyle .15x=300

In this case, Malcolm had $2,000. Since he spent $300 of it on a bicycle, he has only $1,700 left.

Example Question #3 : How To Find The Whole From The Part With Percentage

If 45 is 15% of \displaystyle x, find the value of \displaystyle x.

Possible Answers:

\displaystyle 30

\displaystyle 275

\displaystyle 300

\displaystyle 450

\displaystyle 33.3

Correct answer:

\displaystyle 300

Explanation:

The key to this problem is identifying that "15% of \displaystyle x" is the same as \displaystyle 0.15x. With this information, we can write out the simple equation

\displaystyle 45=0.15x

Dividing both sides by \displaystyle 0.15 gives us

\displaystyle x=300

Example Question #4 : How To Find The Whole From The Part With Percentage

 % of what number is 900?

Possible Answers:

\displaystyle 13,500

\displaystyle 60,000

\displaystyle 12,000

\displaystyle 120,000

\displaystyle 135,000

Correct answer:

\displaystyle 60,000

Explanation:

 % of a number, or, equivalently, 1.5% of a number, is the same as 0.015 multiplied by that number. If we call that number \displaystyle x, then 

\displaystyle 0.015x=900

\displaystyle x = 900\div 0.015 = 60,000

Example Question #6 : How To Find The Whole From The Part With Percentage

Dana spent 24% of her savings on a laptop that costs $900. How much savings does she have left?

Possible Answers:

\displaystyle 3250

\displaystyle 3750

\displaystyle 2850

\displaystyle 3550

\displaystyle 4500

Correct answer:

\displaystyle 2850

Explanation:

We know that prior to her purchase, $900 was 24% of Dana's Savings. Therefore, Dana's total savings prior to her purchase can be modeled as \displaystyle 0.24x=900, where \displaystyle x is Dana's total savings. Solving for \displaystyle x would give you \displaystyle x=3750, which indicates that Dana's savings was $3750 prior to her purchase. After her purchase, she will have $2850 left.

Example Question #6 : Whole And Part

There are 36 blue marbles in a bag. If blue marbles made up 24% of the marbles in the bag, what is the total number of marbles are in the bag?

Possible Answers:

\displaystyle 144

\displaystyle 148

\displaystyle 150

\displaystyle 152

Correct answer:

\displaystyle 150

Explanation:

If \displaystyle x is the total number of marbles in the bag, then \displaystyle 0.24x=36, since 24% of marbles in the bag are blue and there are 36 marbles. Solving for this equation will give you \displaystyle x=150, which means there must be a total of 150 marbles in the bag.

Example Question #3 : Whole And Part

12% of the students at a certain high school have perfect attendance. If 27 students have perfect attendance, how many total students does the school contain?

Possible Answers:

\displaystyle 248

\displaystyle 550

\displaystyle 180

\displaystyle 225

\displaystyle 300

Correct answer:

\displaystyle 225

Explanation:

From the given information here, we know that 12% of the total number equals 27. Mathematically, if we use \displaystyle x to represent the total that we are looking for, we can write this as 

\displaystyle (0.12)(x)=27

The next step is dividing both sides by \displaystyle 0.12.

\displaystyle \frac{27}{0.12}=225

so there are 225 students in the school.

Example Question #3 : How To Find The Whole From The Part With Percentage

\displaystyle 4 is \displaystyle 48\% of what?

Possible Answers:

\displaystyle \small 1.2

\displaystyle \small 1.92

\displaystyle 12

\displaystyle \small 0.08\overline{3}

\displaystyle \small 8.\overline{3}

Correct answer:

\displaystyle \small 8.\overline{3}

Explanation:

To figure out the value, translate the question into an equation, knowing that "is" means equals, and "of" means multiply:

\displaystyle \small 4 = 48\%*x

To solve, turn the percentage into a decimal:

\displaystyle \small 4=0.48*x now divide both sides by 0.48

\displaystyle \small 8.\overline{3}=x

Example Question #9 : How To Find The Whole From The Part With Percentage

\displaystyle 10 is \displaystyle 180\% of what number?

Possible Answers:

\displaystyle 0.18

\displaystyle \small 1.8

\displaystyle \small 5.\overline{5}

\displaystyle \small 55.\overline{5}

\displaystyle 18

Correct answer:

\displaystyle \small 5.\overline{5}

Explanation:

To determine the whole, translate the question into an equation, knowing that "is" means equals and "of" means multiply:

\displaystyle \small 10 = 180\%*x convert the percentage into a decimal:

\displaystyle \small 10 = 1.8*x divide both sides by 1.8

\displaystyle \small 5.\overline{5}=x

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