Buying coin riyals for paper riyals with increase

Q: Is it Haram (prohibited) or Halal (lawful) to exchange nine coin Riyals for ten paper Riyals and give chewing gum or Miswak (tooth-cleansing stick) in addition?

A: Having studied the inquiry and reviewing the previous declarations concerning this issue, the Committee saw that there is no harm in exchanging unequal Saudi coins for Saudi paper Riyals, as they are made of two different materials, provided that the exchange is performed in the same setting. (Part No. 13; Page No. 458) May Allah grant us success. May peace and blessings of Allah be upon His slave and Messenger Muhammad, his family and Companions!