Here is a snippet of section A of the curious multiple-choice entrance exam into the exclusive BrainBashers puzzle club.
Q1. The first question with B as the correct answer is:
A. Q1
B. Q4
C. Q3
D. Q2
Q2. The answer to Q4 is:
A. D
B. A
C. B
D. C
Q3. The answer to Q1 is:
A. D
B. C
C. B
D. A
Q4. The number of questions that have D as the correct answer is:
A. 3
B. 2
C. 1
D. 0
Q5. The number of questions that have B as the correct answer is:
Answers
Q1. C (the first question with B as the correct answer is Q3)
Q2. D (the answer to Question 4 is C)
Q3. B (the answer to Question 1 is C)
Q4. C (the number of questions that have D as the correct answer is one)
Q5. B (the number of questions that have B as the correct answer is two)
Reasoning
A complicated, and sometimes, confusing answer!
Can Q1 be A? No, because this would tell us that Q1 was the first question with B as the answer, which would be a contradiction (as we've just assumed Q1 was A).
Can Q1 be B? No, because this would tell us that Q4 was the first question with B as the answer, which would be a contradiction (as we've just assumed it was Q1).
Can Q1 be C? Possibly, because Q3 points back to Q1 correctly, and is logically consistent.
Can Q1 be D? No, because:
Q2 would be B Q4 would be A, which means that we have three questions with D which means that Q3 would have to be D, and this would tell us that Q1 is A, which would be a contradiction (as we've just assumed that Q1 is D).
Therefore, Q1 is C, which means that Q3 is B.
We can ignore Q2 for a moment, as it asks us about Q4, and look at Q4 first.
Looking at Q4 (how many questions have D as the answer) it can't be D (zero), as this would contradict itself.
It can't be A (three) as we only have two other questions without an answer.
If Q4 was B, then the remaining questions (Q2 and Q5) would both have to be D, and:
Q5 being D would mean that only one question was B, which would be a contradiction (as Q3 is already B, and we've just assumed that Q4 is also B).
So Q4 must be C, which means that Q2 is D.
Looking at Q5, it can't be A (as Q3 is B), it can't be D (as Q4 tells us that we only have one question with D as the answer, Q2). It can't be C as we don't have three questions that are B. So Q5 is B (the two questions are Q3 and Q5).
??
Puzzle 2
Can you complete this grid of letters. Each line is a valid 5-letter word with its first and last letter missing.
The missing letters form a word when read downwards, and the same word appears both at the start and at the end.
What is the missing word?
L
U
R
A
D
A
A
G
L
L
P
H
R
U
I
Note: this puzzle is not interactive, and the squares cannot be clicked.
In each of these sentences, can you replace the missing number.
The number is written as a word (e.g. five, twenty-four, thirty-three), and each sentence is correct after the replacement.
This sentence contains ? X. Slightly trickier, this sentence contains ? R's. Even trickier, this sentence contains precisely ? E's. This sentence has exactly ? letters. This sentence, hopefully, contains ? letters, one hyphen, five commas, and four Y's. To finish, if this sentence had a T removed, it would contain ? letters!
Hint
Start by counting the letters you're already given.
Answers This sentence contains one X.Slightly trickier, this sentence contains four R's.Even trickier, this sentence contains precisely ten E's.This sentence has exactly thirty-nine letters.This sentence, hopefully, contains seventy-five letters, one hyphen, five commas, and four Y's.To finish, if this sentence had a T removed, it would contain sixty-two letters!
