Question

21 is what percent of 40?

Answer 1

Divide 21 with 40

21/40 = 0.525

To change the decimal into a percentage, move the decimal point to the right two place values

0.525 = 52.5%

52.5% is your answer

hope this helps

Answer 2

1. We assume, that the number 40 is 100% - because it's the output value of the task.

2. We assume, that x is the value we are looking for.

3. If 100% equals 40, so we can write it down as 100%=40.

4. We know, that x% equals 21 of the output value, so we can write it down as x%=21.

5. Now we have two simple equations:

1) 100%=40

2) x%=21

where left sides of both of them have the same units, and both right sides have the same units, so we can do something like that:

100%/x%=40/21

6. Now we just have to solve the simple equation, and we will get the solution we are looking for.

7. Solution for 21 is what percent of 40

100%/x%=40/21

(100/x)*x=(40/21)*x       - we multiply both sides of the equation by x

100=1.90476190476*x       - we divide both sides of the equation by (1.90476190476) to get x

100/1.90476190476=x

52.5=x

x=52.5

now we have:

21 is 52.5% of 40