The solution to the problem is as follows:
The formula for permutation would be:
P (n,r) = n! / (n-r) !
5*4*3*2 = 120
Therefore, there are 120 permutations exist of the letters p, q, r, s, and t, taking four at a time.
I hope my answer has come to your help. God bless and have a nice day ahead!
