Since 1 US Dollar is equal to 7.82045 Hong Kong Dollars, we could say that n United States Dollars are equal to 7.82045 times n Hong Kong Dollars. In other words, we could use the following formula:
Hong Kong Dollars = United States Dollars x 7.82045
For example, let's say that we want to convert 2.0 United States Dollars to Hong Kong Dollars. Then, we just replace United States Dollars in the abovementioned formula with 2.0:
Hong Kong Dollars = 2.0 x 7.82045
That is, 2.0 United States Dollars are equal to 15.6409 Hong Kong Dollars.