Final answer:
Fletcher and Patsy eat 1/2 of the tomato altogether.
Step-by-step explanation:
To find the fraction of the tomato that Fletcher and Patsy eat altogether, we need to add the fractions 3/8 and 1/8. Since the denominators are the same, we can add the numerators: 3 + 1 = 4. The total fraction they eat is 4/8. However, we can simplify this fraction by dividing both the numerator and the denominator by their greatest common factor, which in this case is 4. So, 4/8 simplifies to 1/2. Therefore, Fletcher and Patsy eat 1/2 of the tomato altogether.