Question

The average of 7 numbers is 128. Find the seventh number if the other six numbers are 127,
133, 118, 129, 122 and 139​

Answer 1

Answer:

Let the number be x.

Average= Addition of all the numbers/ Total numbers

=> 127+133+118+129+122+139+x/7=128

=>768+x/7=128

= >768+x= 128×7

=> 768+x= 869

=> x= 869-768

=> x= 101.

Answer 2

Answer:

Let the number be x.

Average= Addition of all the numbers/ Total numbers

=> 127+133+118+129+122+139+x/7=128

=>768+x/7=128

= >768+x= 128×7

=> 768+x= 869

=> x= 869-768

=> x= 101.