I am currently completing a study guide for an upcoming physics exam, and I have stumbled upon a question to which I have absolutely no clue how to answer, it is an extra credit question and we have thus barely touched on the topics that it involves. The question goes:

When matter combines with an equal amount of antimatter, mass is destroyed and energy appears in this place (but mass energy is conserved). Say 1.0g of matter and 1.0g of antimatter combine. For how long could the energy thus released power the 271hp Honda Accord? Express your answer in an understandable unit of time.

Thanks to anyone who helps! And sorry for the disturbance...