Final answer:
James buys 2 1/10 kilograms of yellow potatoes.
Step-by-step explanation:
To find out how many kilograms of yellow potatoes James buys, we need to multiply the weight of the red potatoes by 3/4.
First, let's convert 2 4/5 kilograms into an improper fraction. 2 4/5 is equivalent to 14/5 kilograms.
Now, multiply 14/5 by 3/4 to get the weight of the yellow potatoes: (14/5) * (3/4) = 42/20 = 2 2/20 = 2 1/10 kilograms of yellow potatoes.