Calculate the Percentage of 21 over 225: Step-by-Step Solution

Question

What is the percentage of 21 over 225?

Video Solution

Solution Steps

00:00 Calculate 21 as a percentage of 225
00:05 Apply the formula for calculating percentages
00:10 Divide one number by the other and proceed to multiply by 100
00:15 Break down 21 into factors of 7 and 3, and 225 into factors of 75 and 3
00:30 Reduce wherever possible
00:40 Break down 75 into factors of 25 and 3, and 100 into factors of 25 and 4
00:55 Reduce wherever possible
01:03 This is the solution

Step-by-Step Solution

To find the percentage of 21 over 225, we'll follow these steps:

  • Step 1: Express 21 as a fraction of 225: 21225 \frac{21}{225} .
  • Step 2: Simplify the fraction.
  • Step 3: Convert the simplified fraction into a percentage by multiplying by 100%.

Now, let's work through each step:

Step 1: The initial fraction is 21225 \frac{21}{225} .

Step 2: Simplify the fraction. We find the greatest common divisor (GCD) of 21 and 225, which is 3.

Divide both the numerator and the denominator by 3:

21÷3225÷3=775 \frac{21 \div 3}{225 \div 3} = \frac{7}{75} .

Now the fraction is simplified to 775 \frac{7}{75} .

Step 3: Convert the simplified fraction into a percentage:

Multiply by 100%: 775×100%=70075% \frac{7}{75} \times 100\% = \frac{700}{75}\% .

Simplify 70075 \frac{700}{75} :

700 divided by 75 equals 9 with a remainder of 25. Thus, 70075=92575% \frac{700}{75} = 9 \frac{25}{75}\% .

Simplify 2575 \frac{25}{75} to 13 \frac{1}{3} (since 25 and 75 can be divided by 25).

Therefore, the percentage is 913% 9 \frac{1}{3}\% .

The solution to the problem is 913% 9\frac{1}{3}\% , which corresponds to choice 4.

Answer

913% 9\frac{1}{3}\%