Find the missing term
R9I, T6G, V11E, ?, Z13A
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → X4C
Each term has three parts: a first letter, a number and a last letter. Each part follows its own pattern, so the three are found one at a time.
First letters R, T, V, ?, Z: each is 2 letters on (R +2 = T, T +2 = V), so the missing letter is V +2 = X
Numbers 9, 6, 11, ?, 13: the 1st, 3rd and 5th terms are 9, 11, 13 (rising by 2), so the 2nd and 4th must form their own series; 6, then 6 − 2 = 4
Last letters I, G, E, ?, A: each is 2 letters back (I −2 = G, G −2 = E), so the missing letter is E −2 = C
The missing term is X4C.
Tip: When the numbers of a series go up and down, look at the alternate terms: here 9, 11, 13 and 6, 4 are two simple series woven together.