​Look at this series: U32, V29, ______, X23, Y20,……. What number should fill the blank?

Given: U32, V29, ______, X23, Y20

Logic: Letter + 1, Number - 3

Like, U + 1 = V, V + 1 = W, W + 1 = X, X + 1 = Y

32 - 3 = 29, 29 - 3 = 26, 26 - 3 = 23, 23 - 3 = 20

W26 is missing term.

 Thus, the correct answer is (d).