Answer:
45
Step-by-step explanation:
The order in which the items are chosen is not important. So we use the combinations formula to solve this question.
Combinations formula:
is the number of different combinations of x objects from a set of n elements, given by the following formula.

How many possible subsets of 2 items can be chosen from this lot?
Combinations of 2 from a set of 10. So

Take the right angled triangle with sides 13, 12 and 5. sine theta will be 12/13
When sin theta < 0 and cos theta < 0 we are in the third quadrant so sin theta will be -12/13
tan theta = sin theta / cos theta = -5/13 / -12/13 = -5*13 / -12*13 = 5/12
Answer:
8 7/10
Step-by-step explanation: