A briefcase has a number-lock system containing a combination of 3 digits (Each digit can be of numbers 0 to 8). If the correct combination is unknown, how much maximum time would be required to open the bag if each “trial” of combination takes 3 seconds?
Answer: B
Maximum number of trials required = 9 * 9 * 9 = 729. Since for each combination trial, 3 seconds are required to open the briefcase is given as 3 * 729 = 2187 seconds = 36.45 minutes.