For this case we have the following function:
f (c) = (9/5) c + 32
Substituting the value of c = 20 we have:
f (20) = (9/5) (20) + 32
Rewriting we have:
f (20) = (9) (4) + 32
f (20) = 36 + 32
f (20) = 68
Answer:
The conversion for this case is given by:
f (20) = 68
option A