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Question: 21 is 15 percent of what number?

Answer: 140

If you want to learn more, then please keep reading, and you won't be disappointed.

Step by step solution for calculating 21 is 15 percent of what number

We already have our first value 21 and the second value 15. Let's assume the unknown value is Y which answer we will find out.

As we have all the required values we need, Now we can put them in a simple mathematical formula as below:

STEP 121 = 15% × Y

STEP 221 = 15/100× Y

Multiplying both sides by 100 and dividing both sides of the equation by 15 we will arrive at:

STEP 3Y = 21 × 100/15

STEP 4Y = 21 × 100 ÷ 15

STEP 5Y = 140

Finally, we have found the value of Y which is 140 and that is our answer.

You can easily calculate 21 is 15 percent of what number by using any regular calculator, simply enter 21 × 100 ÷ 15 and you will get your answer which is 140

Here is a Percentage Calculator to solve similar calculations such as 21 is 15 percent of what number. You can solve this type of calculation with your values by entering them into the calculator's fields, and click 'Calculate' to get the result and explanation.

percent of what number

Sample questions, answers, and how to

Question: Your friend has a bag of marbles, and he tells you that 15 percent of the marbles are red. If there are 21 red marbles. How many marbles does he have altogether?

Answer: 140 marbles.

How To: In this problem, we know that the Percent is 15, and we are also told that the Part of the marbles is red, so we know that the Part is 21.

So, that means that it must be the Total that's missing. Here is the way to figure out what the Total is:

Part/Total = Percent/100

By using a simple algebra we can re-arrange our Percent equation like this:

Part × 100/Percent = Total

If we take the "Part" and multiply it by 100, and then we divide that by the "Percent", we will get the "Total".

Let's try it out on our problem about the marbles, that's very simple and it's just two steps! We know that the "Part" (red marbles) is 21.

So step one is to just multiply that Part by 100.

21 × 100 = 2100

In step two, we take that 2100 and divide it by the "Percent", which we are told is 15.

So, 2100 divided by 15 = 140

And that means that the total number of marbles is 140.

Question: A high school marching band has 21 flute players, If 15 percent of the band members play the flute, then how many members are in the band?

Answer: There are 140 members in the band.

How To: The smaller "Part" in this problem is 21 since there are 21 flute players and we are told that they make up 15 percent of the band, so the "Percent" is 15.

Again, it's the "Total" that's missing here, and to find it, we just need to follow our 2 step procedure as the previous problem.

For step one, we multiply the "Part" by 100.

21 × 100 = 2100

For step two, we divide that 2100 by the "Percent", which is 15.

2100 divided by 15 equals 140

That means that the total number of band members is 140.

Another step by step method

Step 1: Let's assume the unknown value is Y

Step 2: First writing it as: 100% / Y = 15% / 21

Step 3: Drop the percentage marks to simplify your calculations: 100 / Y = 15 / 21

Step 4: Multiply both sides by Y to move Y on the right side of the equation: 100 = ( 15 / 21 ) Y

Step 5: Simplifying the right side, we get: 100 = 15 Y

Step 6: Dividing both sides of the equation by 15, we will arrive at 140 = Y

This leaves us with our final answer: 21 is 15 percent of 140