IBPS RRB Officer Prelims 16 Sep 2017 Paper

(4) Number of selections = Selection of 3 consonants out of 7 × selection of 2 vowels out of 4 =7C34C2
=

7×6×5

1×2×3

×

4×3

1×2

= 35 × 6 = 210
Now, 5 letters of each group can be arranged in 5 ! ways.
∴Required answer = 210 × 5 !
= 210× 5 × 4 × 3 × 2 × 1
= 25200