Concept:In a number series, the differences between successive terms often follow a simple pattern.Explanation:Replace the wrong term 42 with 40.The corrected series becomes 49,48,45,40,33,24,13.Now find the differences:49−48=148−45=345−40=540−33=733−24=924−13=11The differences are 1,3,5,7,9,11, which are consecutive odd numbers.So 42 is the incorrect term, and it should be replaced by 40.Answer:The correct number is 40 (Option D).