Question 1045128
{{{x}}} = number of correct answers
Since the student answered all {{{50}}} questions in the examination,
{{{50-x}}} = number of wrong answers.
If the student loses {{{3}}} marks for every wrong answer and scores {{{2}}} marks for every correct answer,
his score would be calculated as
{{{2x-3(50-x)}}} .
Since his score was {{{65}}} ,
{{{2x-3(50-x)=65}}} .
 
Solving:
{{{2x-3(50-x)=65}}}
{{{2x-3*50+3x=65}}}
{{{2x-150+3x=65}}}
{{{5x-150=65}}}
{{{5x=65+150}}}
{{{5x=215}}}
{{{x=215/5}}}
{{{x=highlight(43)}}}