Question 935193
Length of Road = {{{1287}}} mile.

Let the fuel economy without wind ={{{ x}}}

Let the influence of wind on fuel economy = {{{w}}}

so while going fuel economy = {{{x-w}}}

While returning the fuel economy = {{{x+w}}}

so {{{x-w = 18}}}
&{{{ x+w = 26}}}
{{{2x = 44}}}
{{{x = 22}}}

plugging the value of {{{x}}} we get {{{w = 4}}}

Fuel used in forward journey = {{{1287/18 = 71.5}}} gallons
Fuel used in return journey ={{{ 1287/(26-4)=1287/22 = 58.5}}} gallons

Total fuel used in round trip ={{{ 130}}} gallons.

Total fuel used in non windy condition = {{{1287*2/22 = 117}}} gallons

So the fuel used is more in windy conditions by {{{13}}} gallons.