how many letter sequence does the word tart form ex: tart, attr,ttar, ect....?

Answer 1

no its 4!/2!

look at this you will be clearer
let number of a in the word be m
let number of b in the word be n
let number of c in the word be o
let number of d in the word be 1(one)
number of e in the word be 2(two)
for this number of ways is
(m+n+o+1+2)!/[m! * n! * o! * 1! * 2!]

Answer 2

Pernumerations of 4 items, taken 4 at a time, is 24.

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