Explanation:
he buys 48 bottles for $18.50.
FYI : that means he gets them for
18.5/48 = $0.385416666... per bottle
he sells all 48 bottles for $1.25 per bottle.
that means the revenue (or selling income) is
48 × 1.25 = $60.00
profit is now income minus basic costs :
profit = 60 - 18.5 = $41.50