Here are 6 Letter Equations (6 LE). Can you guess what the letters stand for in these equations. The letters are the first letters to the word.
E.g. Question= 60 S in a M. Answer= 60 seconds in a minute
1) 9 P of SA
2) 1600 PA
3) 54 C in A
4) 10 DS
UPDATE: 5) 135 SS in R
HINT for 5): ∞ R L to R
6) 32 B of L
I am not sure what the most appropriate or correct tags would be for this sort of puzzle. Also, I'm not 100% certain that they are called letter equations.