First, we'll list all the possible dice rolls
{1,1} {1,2} {1,3} {1,4}
{2,1} {2,2} {2,3} {2,4}
{3,1} {3,2} {3,3} {3,4}
{4,1} {4,2} {4,3} {4,4}
Then we find how many rolls have an odd product, which is 4. We then divide this by the total number of rolls (16) to get a probability of 1/4 (since 4/16 simplified is 1/4). Multiply this by 1/2 to get a probability of 1/8 (We do this because of they are independent events. Google it for more info).
So your final answer is 1/8
:)