Since 1 Hong Kong Dollar is equal to 0.12786987961050836 United States Dollars, we could say that n Hong Kong Dollars are equal to 0.12786987961050836 times n United States Dollars. In other words, we could use the following formula:
United States Dollars = Hong Kong Dollars x 0.12786987961050836
For example, let's say that we want to convert 2.0 Hong Kong Dollars to United States Dollars. Then, we just replace Hong Kong Dollars in the abovementioned formula with 2.0:
United States Dollars = 2.0 x 0.12786987961050836
That is, 2.0 Hong Kong Dollars are equal to 0.2557397592210167 United States Dollars.