Selling discount coupons for gas
Question

                We are offering a program to
      sell fuel to people, the details of which are as follows: pay 200 riyaals
      and get coupons for gas worth 210 riyaals plus a free car wash, knowing
      that the amount of 200 riyaals is being paid in advance when you buy the
      gas coupons. Is this offer halaal or haraam?
Praise be to Allah.If
      the matter is as described, it is permissible to sell the coupons for gas
      plus a car wash for the amount stated, because the sale is in fact for the
      amount of gas described plus the car wash, and there is no deception,
      ribaa or jahaalah (purchase of unknown product) involved.