22 buses are running between two places P and Q. In how many ways can a person go from P to Q and return by a different bus? Select the correct option.
A) None of these
B) 462
C) 412
D) 424
E) 442
Explanation :   He can go in any bus out of the 22 buses.   Hence He can go in 22 ways.   Since he can not come back in the same bus that he used for travelling,   He can return in 21 ways.   Total number of ways = 22 x 21 = 462. Answer : Option 462
<result>B</result>
22 buses are running between two places P and Q. In how many ways can a person go from P to Q and return by a different bus?