#211 - CAT EXAM Riddle

There is a shop that reads:
Buy 1 for $1.00
10 for $2.00
100 for $3.00
I needed 913 and still only paid $3.00. How could this be financially viable for the shop-keeper?

They are numbers for houses and it's $1 per digit.

#212 - Hard Maths Puzzle

A high school has a strange principal. On the first day, he has his students perform an odd opening day ceremony:

There are one thousand lockers and one thousand students in the school. The principal asks the first student to go to every locker and open it. Then he has the second student go to every second locker and close it. The third goes to every third locker and, if it is closed, he opens it, and if it is open, he closes it. The fourth student does this to every fourth locker, and so on. After the process is completed with the thousandth student, how many lockers are open?

The only lockers that remain open are perfect squares (1, 4, 9, 16, etc) because they are the only numbers divisible by an odd number of whole numbers; every factor other than the number's square root is paired up with another. Thus, these lockers will be 'changed' an odd number of times, which means they will be left open. All the other numbers are divisible by an even number of factors and will consequently end up closed.

So the number of open lockers is the number of perfect squares less than or equal to one thousand. These numbers are one squared, two squared, three squared, four squared, and so on, up to thirty one squared. (Thirty two squared is greater than one thousand, and therefore out of range.) So the answer is thirty one.

#213 - Crazy Riddle

Why is it against the law for a man living in Delhi to be buried in Mumbai?

Because he is still living

#214 - Albert Einstein Cipher Puzzle

Can you decipher these quotes by Albert Einstein?
Blf xzm mvevi hloev z kilyovn lm gsv ovevo lm dsrxs rg dzh xivzgvw.

You can never solve a problem on the level on which it was created.
Here is the answer key:
A-Z
B-Y
C-X
D-W
E-V
F-U
G-T
H-S
I-R
J-Q
K-P
L-O
M-N
N-M
O-L
P-K
Q-J
R-I
S-H
T-G
U-F
V-E
W-D
X-C
Y-B
Z-A

#215 - Trick Question

Can you circle exactly four of these numbers such that the total is twelve?

1 6 1
6 1 6
1 6 1
6 1 6

Turn the grid upside down. Circle the numbers 1, 9, 1, 1 When you flip it upside down the 6 becomes 9

#216 - Sherlock Holmes Cipher Puzzle

Sherlock, A detective who was mere days from cracking an international smuggling ring has suddenly gone missing. While inspecting his last-known location, you find a note:
710 57735 34 5508 51 7718
Currently, there are 3 suspects: Bill, John, and Todd. Can you break the detective's code and find the criminal's name?

Sherlock Holmes Cipher Puzzle

Bill. If you read the message upside down, you'll notice that the numbers resemble letters and that those letters form legible sentences. The message is 'Bill is boss. He sells oil.'

#217 - IAS Interview RIDDLE

How can you drop a raw egg from a height onto a concrete floor without cracking it?

Concrete floors are very hard to crack

#218 - Statement Question Riddle

Which statement is true out of the following?
One statement here is false.
Two statements here are false.
Three statements here are false.

The second statement

#219 - Sequence Quiz

Find Next Number in the Sequence
2 9 3 1 8 4 3 6 5 7 ?

'2'
This single sequence in fact consists of two sequences: the first sequence is 2-3-4-5-... and the second sequence is 9-18-36-72-... . To make the puzzle harder, all digits have been placed apart. Conclusion: the next term in the sequence is a '2'.

#220 - Puzzle Boat

At the local model boat club, four friends were talking about their boats.

There were a total of eight boats, two in each colour, red, green, blue and yellow. Each friend owned two boats. No friend had two boats of the same colour.

Alan didn't have a yellow boat. Brian didn't have a red boat, but did have a green one. One of the friends had a yellow boat and a blue boat and another friend had a green boat and a blue boat. Charles had a yellow boat. Darren had a blue boat, but didn't have a green one.

Can you work out which friend had which coloured boats?

Alan had a red boat and a green boat.
Brian had a green boat and a blue boat.
Charles had a yellow boat and a red boat.
Darren had a blue boat and a yellow boat.