If 12 persons are seated in a row, the number of ways of selecting 3 persons from them, so that no two of them are seated next to each other is
Choices:
A) 85
B) 100
C) 120
D) 240
E) None of these
The number of ways of selecting 3 persons from 12 people under the given condition :   Number of ways of arranging 3 people among 9 people seated in a row, so that no two of them are consecutive   = Number of ways of choosing 3 places out of the 10[8 in between and 2 extremes]   = 101203 = 10×9×8/3×2×1=5×3×8=120   Answer 120
<result>C</result>
If 12 persons are seated in a row, the number of ways of selecting 3 persons from them, so that no two of them are seated next to each other is