Since 1 Indian Rupee is equal to 3.8938380952312506 Sri Lankan Rupees, we could say that n Indian Rupees are equal to 3.8938380952312506 times n Sri Lankan Rupees. In other words, we could use the following formula:
Sri Lankan Rupees = Indian Rupees x 3.8938380952312506
For example, let's say that we want to convert 2.0 Indian Rupees to Sri Lankan Rupees. Then, we just replace Indian Rupees in the abovementioned formula with 2.0:
Sri Lankan Rupees = 2.0 x 3.8938380952312506
That is, 2.0 Indian Rupees are equal to 7.787676190462501 Sri Lankan Rupees.