In man hour work problems, if 8 men work for 3 hours, 24 man hours work amount is done. Then it is easy to say 4 men are needed to do same work in 6 hours.
Permutation and combination deal with choice and arrangement of a set of objects out of a second set of objects. Permutation deals with such questions as, how many ways can the three letters a, b and c be arranged? In each such permutation or arrangement, ordering is important. On the other hand, Combination deals with such questions as, how many ways can you choose a captain and vice-captain out of a cricket team of 11 players? In a combination, ordering of the elements chosen is not important...
Break up a number into its factors, just as you break up a complex problem into its component simpler sub-problems. Factorization is one of the most basic operations and is used extensively in other more important problem areas of HCF and LCM...
Numbers and arithmetic operations. Number system concepts and methods for solving number problems in competitive exams explained on test example problems. Exercise problems with answers for practice.
