In how many different ways can the letters of the word 'DETAIL' be arranged such that the vowels must occupy only the odd positions?

In how many different ways can the letters of the word 'DETAIL' be arr

1.	In how many different ways can the letters of the word 'DETAIL' be arranged such that the vowels must occupy only the odd positions?
A.	36
B.	18
C.	54
D.	72
Answer» B. 18