The series given below contains a sequence of numbers.

Solution

The series alternates between decreasing and increasing numbers, with the difference between them following a pattern where each step varies by a multiple of 4. Correct sequence following that pattern:   85 - 4 = 81 81 + 8 = 89 89 - 12 = 77 77 + 16 = 93 93 - 20 =  73 The original sequence given was: 85, 84, 81, 88, 77, 92, 72 Analyzing the given sequence: 85 - 1  = 84 84 - 3  = 81 81 + 7  = 88 88 - 11 = 77 77 + 15 = 92 92 - 20 = 72 The incorrect numbers, when compared to the pattern, are: 84 (should be 81), 88 (should be 89), 92 (should be 93), 72 (should be 73).