3 hands of a clock
3 Lines in a Haiku
Hoops in a game of Croquet
x = 75
This is a ditloid. The answer is 9 = gallons in a firkin.
8 = Pints in a Gallon
4 g in a cc is a ditloid, a type of word puzzle, each letter in the ditloid is the beginning of a word , you have the work it out, in this case the answer is Four Ghosts in a Christmas Carol.
6 Strings on a Classical Guitar
6 Dogs in a Greyhound Race.
8 equals fingers on the human hand (plus 2 thumbs)
200 calories in a pint of Guinness
6
4 Ghosts in a Christmas Carol (Charles Dickens)
Gold Medals Won by Team GB at the Beijing Olympics
Erwin Chargaff