Examples with solutions for Quantity, percentage, percentage value: Applying the formula

Exercise #1

Calculate 14 over 90 as a percentage:

Video Solution

Step-by-Step Solution

To solve the problem of converting 1490 \frac{14}{90} to a percentage, let's proceed as follows:

  • Step 1: Calculate 1490 \frac{14}{90} as a decimal.
  • Step 2: Multiply the decimal by 100 to convert it to a percentage.

Step 1: Divide 14 by 90 to obtain 1490=0.155555555... \frac{14}{90} = 0.155555555.... This is a repeating decimal indicated as 0.15 0.1\overline{5} .

Step 2: Convert this decimal to a percentage by multiplying by 100:
0.155555...×100=15.555... 0.155555... \times 100 = 15.555.... This represents the percentage as 15.555...% 15.555...\%.

Therefore, the fraction 1490 \frac{14}{90} as a percentage is 15.555...% 15.555... \%, which matches the choice labeled as "15.555...%".

Answer

15.555...%

Exercise #2

Calculate 25% of 86:

Video Solution

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Identify the given information, which is 25% of 86.
  • Step 2: Convert the percentage to a decimal by dividing by 100.
  • Step 3: Multiply this decimal by the whole number 86.

Now, let's work through each step:
Step 1: The problem gives us 25% of 86. Our task is to find what 25% of 86 is.
Step 2: Convert 25% to a decimal: 25100=0.25\frac{25}{100} = 0.25.
Step 3: Multiply this decimal by 86: 0.25×860.25 \times 86.

Performing the multiplication: 0.25×86=21.50.25 \times 86 = 21.5.

Therefore, the solution to the problem is 21.5.

Answer

21.5

Exercise #3

Calculate 7% of 40:

Video Solution

Step-by-Step Solution

To solve this problem, we will follow a simple process using the percentage formula.

  • Step 1: Identify the percentage and the quantity. Here, the percentage is 7%, and the quantity is 40.
  • Step 2: Apply the percentage formula: Percentage Value=7100×40\text{Percentage Value} = \frac{7}{100} \times 40.
  • Step 3: Calculate the result. First, compute the multiplication: 7×40=2807 \times 40 = 280. Following that, divide by 100: 280100=2.8\frac{280}{100} = 2.8.

Therefore, the solution to the problem is 2.8 2.8 .

Answer

2.8

Exercise #4

A toy costing $40 is reduced by 20%

What is the new price following the discount?

Video Solution

Step-by-Step Solution

408=32 40-8=32

In order to determine percentages, we must make use of the two pieces of information in our possession: the total amount (40)andthediscount(2040) and the discount (20%).</p><p>This information can be inserted into the following formula:</p><p><span class="katex">\( \frac{Price\times\text{Percentage}}{100} Which allows us to find the percentage of something.

We insert the given information:

40×20100= 40\times\frac{20}{100}=
800100= \frac{800}{100}=

8 8

We then discover that the value of the discount is 8.

But we are not finished yet!

We need to subtract the discount from the original amount in order to determine the sale price:
\( 40-8=32

Answer

32