Letter and Symbol Series Questions and Answers

Answer: D

DOWN-NODW-OWND follows the same logic. In CHIP-PHCI-HIPC the first step takes letters 4, 2, 1, 3 of CHIP to make PHCI (P, H, C, I). The second step takes letters 2, 4, 1, 3 of PHCI to make HIPC (H, I, P, C).

Apply the same two steps to DOWN. Letters 4, 2, 1, 3 give N, O, D, W, which is NODW. Letters 2, 4, 1, 3 of NODW give O, W, N, D, which is OWND, exactly as printed. In the other triads at least one of the two steps uses a different rearrangement: for example HAIR gives AIRH in the first step, which is not the 4, 2, 1, 3 pattern.

Answer: A

The series is the block aaz bby ccx repeated. Placing abcabxzyabc in the 11 blanks in order gives a(a)zb(b)yc(c)x(a)az(b)bycc(x)aa(z)bb(y)ccx(a)az(b)by(c)cx, which reads aaz bby ccx aaz bby ccx aaz bby ccx aaz bby ccx without a break.

The other options put a letter other than the required one in an early blank. For example, acbacxzyabc makes the second block read bcy instead of bby, so the repeating pattern breaks.

A quick test of the key is that every third letter in the completed string runs z, y, x, then repeats, with the first letters running a, b, c in pairs.

Answer: A

The letters go B, F, J, N, R, which move four places each time, so the next letter is V. The numbers 113, 125, 142, 164 and 191 differ by 12, 17, 22 and 27, which rise by 5 each time, so the next difference is 32 and the next number is 191 + 32 = 223. The missing term is therefore V-223, option (A). The options beginning with U break the four-place step in the letters, and V-221 does not follow the number pattern, since it would need a difference of 30.

Answer: D

Go through the string 1 3 @ $ 5 6 & 5 % $ # 1 2 # % # 2 * 5 3 @ 4 $ & * and check each symbol for a number before it and a symbol after it. The @ after 3 is followed by $, so it counts. The % after the second 5 is followed by $, so it counts. The # after 2 is followed by %, so it counts. The $ after 4 is followed by &, so it counts. The other symbols fail: $ after @ and the # after $ follow symbols, the & after 6 and the * after 2 are followed by numbers, and the @ after 3 is followed by 4. There are 4 such symbols, option (D).

Answer: D

The series is ABC, GFE, MJG, SNI, ?. Each letter in the cluster follows its own rule. The first letters are A, G, M, S, so each is 6 places after the one before, and the next is Y. The second letters are B, F, J, N, each 4 places on, so the next is R. The third letters are C, E, G, I, each 2 places on, so the next is K.

The cluster that replaces the question mark is therefore YRK. The options ZRK and SRK break the rule for the first letter (it must be Y), and YRL breaks the rule for the third (it must be K). Only YRK follows all three rules.

Answer: B

The blanks are filled by G and P, so the answer is GP.

Take the first letters: A, B, D, _, K, P. They move forward by 1, 2, 3, 4 and 5 places (A to B is +1, B to D is +2, D to G is +3, G to K is +4, K to P is +5), so the first blank is G. Take the second letters: Z, Y, W, T, _, K. They move back by 1, 2, 3, 4 and 5 places (Z to Y, Y to W, W to T, T to P, P to K), so the second blank is P.

The other options, HP, GO and HQ, each fail at least one of the two letter patterns.

Answer: B

The next term is HA.

The first letters of the terms after the first form the Fibonacci numbers 1, 2, 3, 5 and 8, which are the letters A, B, C, E and H. The second letters follow a pair-wise pattern: A, A, then F, F, then A, A. So the sixth term has first letter H and second letter A.

IA, EB and DB break either the Fibonacci pattern of the first letters or the pairing of the second letters.

Another way to see it is to look at the pairs of letters one by one: AA, BA, CF, EF, then HA. The first letters A, B, C, E, H are the 1st, 2nd, 3rd, 5th and 8th letters, the Fibonacci numbers, so the next is H. The second letters repeat in pairs, so after two Fs come two As, and the next second letter is A.

Answer: B

The missing cluster is RRV. Write each letter as its place in the alphabet and look at each position of the clusters separately. First letters: H(8), M(13), ?, W(23), B(2, that is 28 after wrapping): each step adds 5, so the third is R(18). Second letters: X(24), U(21), ?, O(15), L(12): each step subtracts 3, so the third is R(18). Third letters: K(11), C(3), ?, P(16), K(11): the steps are −8, −7, −6, −5, so the third is 3 − 7 = −4, which is 22 after wrapping, V. The cluster is RRV. RRU, RSV and SRV each break at least one of these three patterns.

Answer: B

The missing group is TUVWX.

Two patterns run together. Each group is one letter longer than the last: BC has 2 letters, FGH 3, LMNO 4, so the next has 5. And the gap between groups grows by one each time: after C, the letters D and E are skipped (2); after H, I, J and K are skipped (3); so after O, four letters, P, Q, R and S, are skipped, and the next group starts at T.

That gives T, U, V, W, X. RSTUV and STUVW start too early (skipping two or three letters after O), and UVWXY starts too late (skipping five).

Answer: D

The missing term is VH15. Take the three parts of each term separately. First letters: P, Q, S, ?, Z move by +1, +2, +3, +4, so the missing first letter is V. Second letters: Q, M, J, ?, G move by -4, -3, -2, -1, giving H. Numbers: 1, 3, 7, ?, 31 follow the rule double and add 1: 1, 3, 7, 15, 31, so the number is 15. The term is VH15. UI17, UG28 and VH25 fail at least one of the three rules: the number 25 is not 15, and 17 and 28 do not fit the doubling pattern.