d The average of two numbers is XY.If one number is equal

# Word Problem 11

Word Problem 11: The average of two numbers is XY.If one number is equal to X ,the other number is equal to_________?

a). X                        b). 2Y                                c). XY-X                         d). 2 XY – X

Solution:

We know the average of a given number of terms is calculated by dividing the sum of terms by their number.

There are two numbers and one number is given as X

We suppose the other number is Y

then their sum = X+Y

their number (number of terms) = 2

so,

$Average= \frac{X+Y}{2}$

But the average is XY (given)

So,

$XY=\frac{X+Y}{2}$

Hence,

$2XY=X+Y$

$Y=2XY-X$

So option d is correct!

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