A letter lock contains 5 rings each marked with four different letters. The number of all possible unsuccessful attempts to open the lock is

Step-by-step solution

Number of options on 1st ring =4 Number of options on 2nd ring =4 Number of options on 3rd ring =4 Number of options on 4rd ring =4 Number of options on 5rd ring =4 Total number of ways of all the options =4 4 4 4 4=1024 Number of all possible unsuccesful attempts to open the lock is =1024-1=1023