The pattern followed here is, 217:513=(6)3+1:(8)3+1 Similarly, I. 26:342=(5)2+1:(7)3−1 II. 126:344=(5)3+1:(7)3+1 III. 64:217=(8)2:(6)3+1 IV. 49:730=(7)2:(9)3+1 So, option (2) is followed this pattern but other three options not followed. Hence, "126 : 344" is the correct answer.