What is the next value 4 d 7 g 10 j 13

First, look at the overall pattern. The overall pattern is number, letter, number, letter and so on. Thus, the next value should be a letter. Consider the letters in the sequence: d , g , j. Between d and g, there are 2 missing letters --e and f. Between g and j, there are 2 missing letters--- h and i. Now we know that the next value will be a letter and that it will be two letters away from the letter j. Thus, the next value is "m".