Answer:
The value is [tex]\eta = 54.4 \%[/tex]
Explanation:
From the question we are told that
  The work input is  [tex]W = ( 245 + A ) \ J[/tex]
   The heat delivered is [tex]Q = (142 + B) \ J[/tex]
   The value of A is  A =  14
    The value of B  is  B  = 72
Generally the efficiency of the heat engine is mathematically represented as
     [tex]\eta = \frac{W}{Q_t}[/tex]
Here  [tex]Q_t[/tex] is the total out energy produce by the heat engine and this is mathematically represented as
      [tex]Q_t= Q + W[/tex]
=> Â Â Â Â [tex]Q_t= 245 + A + 142 + B[/tex]
=> Â Â Â Â [tex]Q_t= 390 + A+B[/tex]
So
        [tex]\eta = \frac{245 + A }{390 + A+ B}[/tex]
=> Â Â Â Â Â [tex]\eta = 0.544[/tex]
=> Â Â Â Â Â [tex]\eta = 0.544 *100[/tex]
=> Â Â Â Â Â [tex]\eta = 54.4 \%[/tex]