what is the tens digit of 7 ^ 1213 ?
"7 ^ 1 = 7 7 ^ 2 = 49 7 ^ 3 = 343 7 ^ 4 = 2401 7 ^ 5 = 16807 7 ^ 6 = 117649 we should see this as pattern recognition . we have a cycle of 4 . ( we can multiply the last 2 digits only as we care about ten ' s digit ) 0 , 4 , 4 , 0 . 1213 = 4 * 304 + 1 the ten ' s digit will be 0 . answer a"
floor(divide(reminder(power(7, reminder(1213, add(const_4, const_1))), const_100), const_10))