Since 1 Sri Lankan Rupee is equal to 0.6393431197227003 Guyanaese Dollars, we could say that n Sri Lankan Rupees are equal to 0.6393431197227003 times n Guyanaese Dollars. In other words, we could use the following formula:
Guyanaese Dollars = Sri Lankan Rupees x 0.6393431197227003
For example, let's say that we want to convert 2.0 Sri Lankan Rupees to Guyanaese Dollars. Then, we just replace Sri Lankan Rupees in the abovementioned formula with 2.0:
Guyanaese Dollars = 2.0 x 0.6393431197227003
That is, 2.0 Sri Lankan Rupees are equal to 1.2786862394454006 Guyanaese Dollars.