find the sum of the number of combinations possible by using 12 , 34 such that no number is repeated ( ex : - 12234322 are invalid 12344321 are valid ) more than once .
total no . formed = 4 ! = 4 * 3 * 2 * 1 = 24 each digit will be used at each positions , 6 times sum of digits at unit place = 6 * 1 + 6 * 2 + 6 * 3 + 6 * 4 = 6 * ( 1 + 2 + 3 + 4 ) = 60 this sum will be same for hundred , tens & unit places sum of all 4 digit numbers formed using digits 12 , 34 = 1000 * 60 + 100 * 60 + 10 * 60 + 60 = 60 * ( 1000 + 100 + 10 + 1 ) = 60 * 1111 = 66660 answer : a
add(add(add(multiply(multiply(add(add(const_1, const_2), const_3), add(add(add(const_1, const_2), const_3), reminder(34, const_10))), const_1000), multiply(multiply(add(add(const_1, const_2), const_3), add(add(add(const_1, const_2), const_3), reminder(34, const_10))), const_100)), multiply(multiply(add(add(const_1, const_2), const_3), add(add(add(const_1, const_2), const_3), reminder(34, const_10))), const_10)), multiply(add(add(const_1, const_2), const_3), add(add(add(const_1, const_2), const_3), reminder(34, const_10))))