Multiply tokens (t) by the price: 1.25t
Subtract this from the total amount he has (25) the total needs to be less than or equal to $5 so he can buy lunch:
25 - 1.25(t) <= 5
Now solve for t:
Subtract 25 from both sides:
-1.25(t) <= -20
Divide both sides by -1.25
T <= 16
He can buy a maximum of 16 tokens.
