Spending amount (A) | DBS$ used (B) | Converted at DBS$1 = HK$1.25 to set off the spending amount (C) (C = B×1.25) (B) | Amount payable after set off (D) (D = A – C) | |
Example 1 | HK$100 | DBS$80 | HK$100 | HK$0 |
Example 2 | HK$200 | DBS$100 | HK$125 | HK$75 |
Example 3 | HK$386 | DBS$308 | HK$385 | HK$1 |