A number increased by 3/4 of the number is 21. Find the number

Question

A number increased by 3/4 of the number is 21. Find the number 

Answer 1

Hi Hali,

 

Where are you having difficulty with this problem? A good start would be to convert the words given (i.e. "number" and "increased") into mathematical terms and operators. Finally, we have to think about what you're solving for and what you're missing. Best of luck working this one out!

 

-Brandon

Answer 2

Let x be the number before the increase.

If we increase this number by 3/4 we get 21. This can be expressed as:

 

x + (3/4)x = 21

 

Solving for x:

 

x (1 + 3/4) = 21

 

(7/4) x = 21

 

x = (21) (4/7)

 

x = 12

 

So the number is 12

 

You can check this by increasing by 3/4 of the number which is 9.

Adding the number with the increase gives 12 + 9 =21.