Letter and Symbol Series Questions and Answers

Answer: C

Correct answer: $

These are the shifted characters of the number row, taken in reverse: shift-8 gives *, shift-7 gives &, shift-6 gives ^, shift-5 gives %. Continuing backwards, shift-4 gives $. Symbol series almost always depend on keyboard order rather than on any mathematical rule, so the keyboard is the thing to picture. # is shift-3 and would be the term after next. Symbol series depend on the physical keyboard rather than on any ordering intrinsic to the characters, so the row of number keys is what should be pictured.

Answer: D

Correct answer: }

The series steps through the bracket pairs in the order they appear on the keyboard, giving each opening bracket followed by its closing partner: round, then square, then curly. The curly pair has been opened but not closed, so the next symbol is }. Recognising that the terms come in pairs is the whole of the problem; the individual symbols carry no arithmetic. There are only three bracket pairs in common use, so a series of this kind can run for at most six terms before it must repeat or stop.

Answer: A

Correct answer: ]

The symbols come in matched pairs: angle brackets, then curly braces, then square brackets. Each opening symbol is followed immediately by its closing partner, and the square bracket has been opened, so the next is ]. The order of the pairs follows their arrangement on the keyboard rather than any convention of mathematics. The order of the pairs follows the keyboard from the comma and full stop keys leftward to the square brackets, not any mathematical convention.

Answer: B

Correct answer: $

These are the shifted characters of the top row read left to right: shift-backtick gives ~, then shift-1, shift-2 and shift-3 give !, @ and #. The next along is shift-4, which is $. Starting the count at the backtick rather than at the 1 key is what distinguishes this series from the one that begins with an exclamation mark. Starting at the backtick rather than at 1 shifts every term by one key, which is the single decision that determines the answer.

Answer: C

Correct answer: (

The series runs through the shifted number keys in ascending order: shift-5 gives %, shift-6 gives ^, shift-7 gives &, shift-8 gives *. The next key is 9, whose shifted character is (. The closing bracket sits on the 0 key and would be the term after next, which is why it is the most attractive wrong answer. The closing bracket on the 0 key would be the term after next, which is why it is the most attractive of the wrong answers.

Answer: D

Correct answer: GHJ

Read the triples column by column. The first letters run A, C, E - two apart - so the next is G. The second letters run B, D, F, also two apart, giving H. The third letters run D, F, H, giving J. The next triple is GHJ. Within each triple the letters sit at gaps of one then two, which is preserved in the answer. GHI makes the internal gaps equal and is the natural but incorrect tidy-up.

Answer: A

Correct answer: DFH

Each triple holds three letters two places apart, and each triple starts one place after the last: A, B, C. The next starts at D, so its letters are D, F and H, giving DFH. Two rules operate together - the internal spacing and the step between triples - and the answer must satisfy both. DEF keeps the correct start but collapses the internal spacing to one. Both the internal spacing and the step between triples must be honoured, and an answer that satisfies only one of them will always be among the options offered.

Answer: B

Correct answer: GWH

Three strands run at once. The first letters climb A, C, E by two, so the next is G. The middle letters fall Z, Y, X by one, so the next is W. The third letters climb B, D, F by two, giving H. The triple is GWH. Note also that the first and third letters of each triple are one apart, which is a useful check on the answer once assembled. Three strands running at once is the most this topic attempts, and separating them into columns on paper is the only reliable way to handle it.

Answer: C

Correct answer: YZA

Each triple is three consecutive letters, and the triples follow one another without a gap: P, Q, R then S, T, U then V, W, X. The next three letters are Y, Z and then the alphabet wraps round to A, giving YZA. The wrap is the whole point of the question; a series that simply ran out of letters would have no answer at all. Without the wrap the series would simply run out at X, so the presence of a question mark is itself evidence that the alphabet is meant to be treated as a loop.

Answer: D

Correct answer: M

The gaps alternate: A to C is +2, C to F is +3, F to H is +2, H to K is +3. The next gap returns to +2, and two beyond K(11) is position 13, which is M. Alternating gaps are read by writing the differences underneath and looking for the repeat; assuming a single constant gap gives either L or N depending on which of the two steps is chosen. Alternating gaps advance the series five places for every two terms, so the odd-position terms A, F and K form a five-step series of their own.