Answer: Matt has 42 marbles and Maya has 48 marbles.
Explanation:
Matt's has more than 41, but less than 43 marbles. Since each marble has to correspond to a whole and real number, the only number between 41 and 43 is 42. Likewise the only number between 47 and 49 is 48 since Maya has more than 47 marbles but less than 49 marbles.