The average of two numbers is 16. If one of the numbers is 11, what is the other numbers?

Question

 I need to figure out what the other number is

Answer 1

When you take averages you need to add the numbers together and then divide by the amount of numbers you are adding. For example (x + y + z)/3 or (x + y)/2... In this problems they are telling us that the average is 16 and one of the numbers is 11. Therefore, we have the equation (11+x)/2=16.  If we solve for x you multiply the 16 by 2 and subtract 11. This will equal 21; this will be your second number. To check the answer, we plug in 21 for x and we have (11+21)/2=16;  32/2 = 16;  16=16. 

 

Another trick when you are taking the average of two numbers is that the difference between the average and the numbers must be the same. For example, in this case one number is 11 and the average is 16, the difference between them is 5; therefore the difference between the second number and the average must also be 5. Making the second number 21; 21-5 = 16;  16-5 =11.

 

 

Let me know if you have any other questions! Take care and good luck!

 

-Daniel

Answer 2

the underlying formula that you want to use to solve this one is

(11 + x) / 2 = 16

solving that algebraically for the value of "x" yields

11 + x = 32

x = 21