Will a 13% increase followed by a 13% decrease result in no net change?

No it would result in a change.

Step-by-step explanation:

Lets take an example, 100. If 100 is increased by 13% it is 113. However, if you decrease 113 by 13% it is equal to 98.31. Thus, the result would change. This is a trick question, to fool people.

If pq passes through the center, it is a diameter. since prq is a right triangle, r = 90 degrees. if arc qr is 100 degrees, then angle p = half of arc qr = 50 degrees. since the sum of the internal angles of a triangle is 180: p + q + r = 18050 + q + 90 = 180q = 40 degrees.