NIACL Model Paper 10 with solutions for free online practice

(3) There are 7 letters in theword ‘DRASTIC’ including 2 vowels (A,I) and 5 consonants (D,R,S,T,C,). Considering two vowels as one letter, we have 6 letters which can be arranged in 6! ways. But corresponding to each way of these arrangements, the vowels can be put together in 2! ways.Hence, required number of words = 6! × 2!
= 720 × 2 = 1440