The unit digit of 73^350 is same as that of 3^350.
Power of 3 has cyclicity of 4. That means set of 4 values repeats {3,9,7,1}.
3^1=3 (3)
3^2=9 (9)
3^3=27 (7)
3^4=81 (1)
3^5=243 (3)
and cycle continues.
Hence 3^350= 3^348 * 3^2
=3^2
=9.
Hence Option E.
Kudos if it helps.
Power of 3 has cyclicity of 4. That means set of 4 values repeats {3,9,7,1}.
3^1=3 (3)
3^2=9 (9)
3^3=27 (7)
3^4=81 (1)
3^5=243 (3)
and cycle continues.
Hence 3^350= 3^348 * 3^2
=3^2
=9.
Hence Option E.
Kudos if it helps.
