Do you know how to do modulo-calculations? That is, how to add and multiply residu-classes modulo 10?
This problem is actually quite simple if you can do this and make one simple observation. Namely, mod 10 for all
no i am in kindda in high school still lol
sorry =/ but u can tell me whateva i need to learn to solve this thereby i can learn some of it online,
yes i knw n! mod 10 = 0
yes i did make that observation that n! in mod 10 is 0 for all values of n more than equal to 5...but still lost :L