Arat having to press the lever a certain number of times before it would receive the pellet of food is an example of which of the following?
a. fixed ratio
b. variable ratio
c. fixed interval
d. variable interval

Fixed Ratio

Explanation:

In the example we can see that rat has to press it a number of times that means that no matter how other factors change the ratio of pressing of the to the pellet of food remains same.

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