1:15 pm + 5 minutes =1:20 PM You add 5 minutes because your watch is slow then subtract 3 minutes because you thought the watch was 3 minutes fast. real time is 1:17 PM 1:20 pm - 3 minutes = 1:17 PM
The concept of the question above is Permutation where in we are to arrange to arrange the 6 students from which there are 20 students. This is the "permutation of 20 taken 6" or 20P6. The numerical value of the permutation is equal to 27907200.
