Probably supposed to be 42 M of L but copied incorrectly.
42 = Meaning of Life.
(Although not strictly true either, 42 was the answer to the ultimate question of life the universe and everything.)
In bingo, 22 is referred to as "Two Little Ducks"22 Equals 2 Little Ducks
17 yak liquorish
49 Balls in the Lottery (UK)
42000mL is 42 liters.
River Boyne 112 kilometres long.
50 is L in Roman Numerals
Meaning of Life Hitchhiker's guide to the galaxy reference.
12 Lines on the Underground
9=l in a gb
9 Points of the Law that Possession Is
18 Minimum Age for a (French/Finnish/Full/Foreign) Driving License
14 Lines in the London Underground System