Question

what is the difference between a combination and a premutation? Give supporting example.

Answer 1

The basic difference between permutation and combination is the order of objects. In combination, the order does not matter at all but in permutation the order of objects is matter .

We also say that combination is the different way of selecting a group from a members of a set without any ordering. Mathematically, combination is defined as

ⁿC_r = n!/ (r!)(n-r)! for example l

All possible combinations of  letters A,B,C–

When three out of three letters are to be selected, then the only combination is ABC

When two out of three letters are to be selected, then the possible combinations are AB , BC, CA

Permutation is defined as the way of arranging a set of object in sequential order.

Mathematically ⁿP_r = n!/(n-r)! for example

All possible permutation created with letters A, B, C –

• By taking all three at a time are ABC, ACB, BAC, BCA, CAB, CBA.
• By taking two at a time are AB, AC, BA, BC, CA, CB.