Let's assume that the price of crude oil is $37.00 per barrel. At 19.5 gallons of gasoline per barrel, this means that a gallon of gasoline in its crude oil form costs $1.90.
Johnny Tillotson is 77 years old (birthdate: April 20, 1939).
Usage: Till is a variant of until that is acceptable at all levels of language. Until is, however, often preferred at the beginning of a sentence in formal writing: until his behaviour improves, he cannot become a member.