In arranging alphabet letters, CIRCLE, how many times does at least one letter stand between C and C?
A. 180 B. 200 C. 210 D. 240 E. 250
OA IS D
A. 180 B. 200 C. 210 D. 240 E. 250
OA IS D
TOTAL NO OF WAYS = NO OF WAYS WITH C&C NEXT TO EACH OTHER + NO OF WAYS WITH AT LEAST ONE LETTER B/N C&C
=> NO OF WAYS WITH AT LEAST ONE LETTER B/N C&C = TOTAL NO OF WAYS - NO OF WAYS WITH C&C NEXT TO EACH OTHER
TOTAL NO OF WAYS : 6! / 2! = 360
NO OF WAYS WITH C&C NEXT TO EACH OTHER: 5! = 120
NO OF WAYS WITH AT LEAST ONE LETTER B/N C&C: = 360 - 120 = 240
HENCE D
