Determine the total number of individual rational terms in the multinomial expansion of each of the following expressions:

(I) (√12 + √32 + √48 + √50)⁶

(II) (√12 + √32 + √48 + √50)⁸

Hence or otherwise, determine the total number of individual rational terms in the multinomial expansion of (√12 + √32 + √48 + √50)²ⁿ in terms of n, whenever n is a positive integer.