Find the 2nd term of an arithmetic sequence with t1 = 4 and t5 = 6.
11/2
5
9/2
4

Tn = t1 + (n-1)*d, so t5 = t1 + 4*d, then d = (t5 -t1)/4 = 1/2,

Then t2 = t1 + d = 4+1/2 = 9/2=4.5, so The third one!

I’m not absolutely sure but i think it’s 7x6x5x4x3x2=5040 because as the first character you can take any of the 7 given then you are left with 5 then 6 then 4 etc.