Question

The average of three numbers is 16. If one of the numbers is 18, what is the sum of the other two numbers?

Answer 1

Answer:

Let the two numbers be X and Y

Other number is 18

Given that, average of three numbers is 16.

X+Y+18/3 = 16

X+Y+18 = 16*3

X+Y+18 = 48

X+Y = 48-18

X+Y = 30

Therefore, sum of two numbers is 30

Answer 2

The sum of the other two numbers will be 30.

Given,

The average of the three numbers is 16,

One of the numbers = 18.

To find,

Sum of the other two numbers.

Solution,

Firstly, one of the numbers is given as 18, and let the other two numbers be a and b.

Now, the average is defined as the sum of the given numbers divided by the number of numbers present, that is how many numbers are there.

Let the average of the three numbers a, b, and 18, be A, then A is given by,

$A=\frac{a+b+18}{3}$     ...(1)

∵ average is given to be 16.

⇒ A = 16.

Substituting in above eq. (1), we get,

$16=\frac{a+b+18}{3}$

Rearranging and simplifying the above equation,

$a +b+18=16 \times 3$

$\implies a +b=48-18$

$\implies a +b=30$

Since a and b are the other two numbers, so above equation gives us the required sum. That is,

the sum of the two numbers other than 18, is 30.

Therefore, the sum of the other two numbers will be 30.