169P, 143H, 221E, 195O, ....... If the series continues, what will be the 5th number?

Answer: C. 273L

The 5th term is 273L. The numbers follow an alternating pattern of subtracting 26 and adding 78 (\(169 - 26 = 143\), \(143 + 78 = 221\), \(221 - 26 = 195\), and \(195 + 78 = 273\)). Meanwhile, each letter corresponds to the alphabetical position of the sum of its number's digits (\(1+6+9=16\) for P, \(1+4+3=8\) for H, \(2+2+1=5\) for E, \(1+9+5=15\) for O, and \(2+7+3=12\) for L).

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