Rice knows the quantity, unit price and total amount. How to calculate the amount of a catty?

Knowing the quantity, unit price and total amount of rice to calculate the amount of one catty of rice is a bit confusing. What does this so-called unit price mean? You already know the unit price. Isn't this unnecessary? Does this unit price mean a ton or a kilogram? So this question feels a bit ridiculous. The normal problem should be to know the quantity and total net quantity of rice, find the quantity or unit price of one catty of rice, and divide the total quantity by the quantity of rice to get the unit price or one catty of rice.