I need help answering this question.

See attachment below and find the equivalent of tan(∠qsr)

Select quivalent or not equivalent to indicate whether the expression above is equivalent or not equivalent to the values or expressions in the last column.

Asa a yogurt shop allows its customers to add, for no charge, 3 toppings to any yogurt purchased. if the store has 18 possible toppings, how many different 3-topping combinations can a customers choose?