What's the unit for number 1,2,4 !

1. 3 cans of cat food for $0.85

This is really simple division once looked at (I took the decimal out of the equation, so I will add it back later):

85/3=28.333…

Since it can't be rounded, it remains as 28, which means that the correct answer is $0.28/can of cat food, once the decimal placement has been refactored.

2. 14 ounces of Olive Oil for $3.59.

359/14=25.642

Since this term is able to be rounded, it becomes 26, since we're rounding to two numbers. Now, we put the decimal back where it was taken out earlier, and we learn that the answer is $0.26/ounce of Olive Oil.

4. 4 pairs of socks for $11.00.

1100/4= 275

This time, there is nothing to round, so after the decimal has been put back in its original spot, the answer becomes $2.75/pair of socks.