Question

The sums of three whole numbers taken in pairs are `11`, `12`, and `17`. What is the middle number (taken in orders)?

Please help...Thanks!!!

Answer 1

`3,8,9" are the 3 numbers"`

Explanation:

`"let the 3 numbers be a, b and c, then"`

`a+b=11to(1)`

`b+c=12to(2)`

`a+c=17to(3)`

`"from equation "(1)color(white)(x)b=11-a`

`"from equation "(3)color(white)(x)c=17-a`

`(2)to11-a+17-a=12`

`-2a+28=12rArr-2a=-16rArra=8`

`(1)tob=11-8=3`

`(3)toc=17-8=9`

`"the 3 numbers are "3,color(red)(8)" and "9`