QUESTION If a man cycles at 10 km/hr, then he arrives at a certain place at 1 p.m. If he cycles at 15 km/hr, he will arrive at the same place at 11a.m. At what speed must he cycle to get there at noon? 1)...
Suppose there are 'n' number of different things. You would like to 'select' or 'arrange' all or some of those things in an order. In how many unique ways can you do so? Permutations and combinations is...