ask if you need further explanations

I'll second that there's something funny here that needs to be clarified in the question: the options are definitely in cents rather than dollars. Good call eltonpereira

If I do the calculation with dollars + cents, I set this up as the original cost being this:

1.2 (dollars) + (30-4)c before discount..

then at an 80% discount that gives me:

1/5(1.2 + (30-4)c)

0.24 + (26/5)c

0.24 + 5.2c

Whereas if I do the calculation all in cents I get this:

120 (cents) + (30-4)c before discount...

then at an 80% discount that gives me:

24 + (26/5)c

24 + 5.2c or Answer E.