Answer:
2/3
Step-by-step explanation:
The largest number with a given numerator is the one with the smallest denominator.
Of 1/4, 1/3, 1/5, the largest is 1/3.
Of 2/4, 2/3, the largest is 2/3.
Since 1/3 and 2/3 have the same denominator, the largest is the one with the largest numerator: 2/3.