Manipal Entrance Test 2016 Math Paper

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 attempt to open the lock is =1024−1=1023