Find the wrong number among the given series. 975, 864, 743, 642, 531, 420

The series follows a pattern of subtracting 111 repeatedly: 975-111=864, 864-111=753, 753-111=642, 642-111=531, 531-111=420. However, the given term is 743 instead of 753. So 743 is the wrong number that breaks the pattern. Checking the actual sequence: 975, 864, 743, 642, 531, 420. Differences: 975-864=111, 864-743=121 (wrong), 743-642=101 (inconsistent), 642-531=111, 531-420=111. The term 743 is incorrect; it should be 753 for a consistent -111 pattern.