Question

the sum of five numbers is 655. the average of the first two numbers is 85 and the third number is 125. find the average of the two numbers

Answer 1

five number in their

sum = 655

first two number sum =

85 × 2 = 170

and third number is 125

170 + 125 = 295

remaining two number sum is

655 - 295 = 360

average = 360/2 = 180

Answer 2

Given ,

Sum of 5 numbers - 655

Average of first 2 numbers = 85

Third number = 125

To find,

Average of the last 2 numbers

Solution,

Now , let the five numbers be a1,a2,a3,a4,a5

Given, a1+a2+a3+a4+a5 = 655

$\frac{a1+a2}{2} = 85\\a1+a2 = 170$

Given a3 = 125

Now, 170+85+a4+a5 = 655

a4+a5 = 655 - 255

a4+a5 = 400

Now , average is sum of two numbers divided by 2.

Here we need average of a4 and a5.

So average = $\frac{a4+a5}{2} \\\\= \frac{400}{2} \\\\200$

Hence the average of last two numbers is 200.