It's 5 permutations of 3 and to solve you calculate 5!/(5-3)!
Basically the problem was the same as asking you "How many ways can you pick three objects from five objects, where the order you pick them matters" which is called a permutation problem.
This is a variables question. In total there are 5 numbers, (it doesnt matter with ones), the question wants you to only use 3 of them at a time and make the most different numbers with 3 digits as possible. Assuming you cant repeat numbers, only use different ones when making the 3 digit number, you do: 5 (the total of numbers given) x 4 (the total minus the number used in the first house of the 3 digit number) × 3 (the total minus the other 2 numbers already used) so: 5x4x3 = 60
I feel like this is easiest explanation yet it went over my head I guess I'm staying there
Hey how did they solve the 1st question?? Is there any formula???
I know I'm dumb