An old man while dialing a 7 digit telephone number remembers that the first four digit consists of one 1’s, one 2’s and two 3’s. He also remembers that the fifth digit is either a 4 or 5 while he has no memorization of the sixth digit, he remembers that the seventh digit is 9 minus the sixth digit. Maximum number of distinct trials he has to try to make sure that he dials the correct telephone number, isA.360B.240C.216D.None of these

Harshit Singh , 2 Years ago

Grade 12th pass