Answer:
The value is 
Explanation:
From the question we are told that
The work input is
The heat delivered is 
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

Here
is the total out energy produce by the heat engine and this is mathematically represented as

=> 
=> 
So

=> 
=> 
=> 