internal plagiarism for a cos

im posting my method

x1+x2+x3+x4+x5=18-x6

where (xi)

is a solution to the first expression

LHS can take values from 4 to 17

length of interval =14

for the second expression

length of expression=5

my ans wud be 5/14

i know my method is wrong ( because of the answer)

please explain what is wrong in it

DID U UNDERSTAND THE PINKED POST(EARLIER ONES...)

IF U HAD THEN I DONT THINK U B ASKING THIS QUES...

IF U DIDNT THEN U MUST...

ITS VERY EASY BUT IMPORTANT CONCEPT IN THAT QUES...

INTERVAL RATIO WONT DO .....

SINCE WE HAVE TO TAKE ^INTERVALC_SOMETHING .....AND ITS RATIO

IS NOT SIMPLE ONE AS U KNOW...

can some one say exactly what is wrong in my method

or how can it modified

or if the method is too dumb please say it