Step-by-step explanation:The successor and predecessor of a whole number are discussed below:SUCCESSORThe successor of a whole number is the number obtained by ADDING 1 to it.Clearly, the successor of 0 is 1; successor of 1 is 2; successor of 2 is 3 and so on.We observe that every whole number has its successor.PREDECESSORThe predecessor of a whole number is one less than the given number.Clearly, the predecessor of 1 is 0; predecessor of 2 is 1; predecessor of 3 is 2 and so on.The whole number 0 does not have any predecessor.We observe that every whole number, other than zero, has its predecessor.Also, if a is the successor of b, then b is the predecessor of a.For example:Find the successor and predecessor of each of the following whole numbers:(i) 1000(ii) 11999(III) 400099(iv) 1000001(v) 99999Solution :(i) 1000The successor of 1000 is (1000 + 1) = 1001.The predecessor of 1000 is (1000 - 1) = 999.(ii) 11999The successor of 11999 is (11999 + 1) = 12000.The predecessor of 11999 is (11999 - 1) = 11998.(iii) 400099The successor of 400099 is (400099 + 1) = 400100.The predecessor of 400099 is (400099 - 1) = 400098.(iv) 1000001The successor of 1000001 is (1000001 + 1) = 1000002.The predecessor of 1000001 is (1000001 - 1) = 1000000.(v) 99999The successor of 99999 is (99999 + 1) = 100000.The predecessor of 99999 is (99999 - 1) = 99998.Please mark as brainliest OK plzThank U .GOOD day