Required unit's digit = unit's digit in (4)¹⁰² + (4)¹⁰³.
Now, 42 gives unit digit 6.
.`.(4)<sup>102</sup> gives unjt digit 6.
.`.(4)¹⁰³ gives unit digit of the product (6 x 4) i.e., 4.
Hence, unit's digit in (264)m + (264)¹⁰³ = unit's digit in (6 + 4) = 0.