If the permutations of a, b, c, d, e taken all together be written dowan in alphabetical order as in dictionary and numbered then the rank of the permutation debac, is

Options

A. 90
B. 91
C. 92
D. 93

Answer

D

Explanation

The letters in alphabatical order are abcde
`a to 4!=24`.
`b to 4!=24" "dc to 3!=6`
`c to 4!=24" "dea to 2!=2`
`da to 3!=6 " becac"to1`
`therefore`The rank of debac=24+24+24+6+6+6+2+1=93