On average in its orbit, Mars is about 228,000,000,000 meters away from the sun (that's 2.28 x 1011 m in scientific notation). Light travels at 300,000,000 meters/second (3x 108 m/s). To get the answer, divide the distance by the speed. You'll find that it takes 760 seconds, or 12 minutes and 40 seconds for sunlight to reach Mars. It takes light about 8 minutes to travel from the Sun to Earth.
Source(s):
http://athena.cornell.edu/kids/cs_calvin_questions.html
12 minutes and 40 seconds for sunlight to reach Mars
