25 Cents for a Postage Stamp
4 corners on a tetrahedron.
This is a Ditloid. The answer is 535 Members of Congress.
This may no longer apply but the Ditloid answer is 12 Provinces of Canada. NOTE There used to be 10 provinces and 2 territories - now increased to 3.
50 Per Cent Equals One-Half
The ditloid "O equals S C in H" stands for "One equals six in hexagons." This type of puzzle uses numbers and letters to represent phrases or titles, often related to common sayings, phrases, or concepts. In this case, it highlights a mathematical or geometric relationship involving hexagons.
3 hands of a clock
-44 Assassination of Julius Caesar (-44 means 44 BC)
25 cents in a quarter
3c-25=17-c 3c+c=25+17 4c=42 c=10.5
-3
10
25 Squares on a Bingo Card.