Start by putting the inequality in the form
[tex]ax+c>d[/tex]in this case c wil be how much he has sold, and d will be how much he needs to sell, and a is the price for the bar.
it would look like this
[tex]2.5x+40>175[/tex]solve it like a regular equation
[tex]\begin{gathered} 2.5x>175-40 \\ 2.5x>135 \\ x>\frac{134}{2.5} \\ x>54 \end{gathered}[/tex]He will have to sell over 54 bars to win the prize.