Answer:
Step-by-step explanation:
step one:
In this problem, we are told that the price of gasoline has tripled in the past twelve years.
step two:
Given that the price 12 years ago was $n and r cent
to get the current price we need to multiply the price twelve years ago by 3
hence n*3 and r*3
this means that the current price is
3n dollar and 3r cent
The price now is 3n dollar and 3r cent