what is the unit digit in 7 ^ 105 ?
"unit digit in 7 ^ 105 = unit digit in [ ( 7 ^ 4 ) ^ 26 x 7 ] but , unit digit in ( 7 ^ 4 ) ^ 26 = 1 unit digit in 7 ^ 105 = ( 1 x 7 ) = 7 . answer b ) 7 ."
reminder(power(const_4.0, const_2), const_10)