You have 8 balls numbered 1, 3, 5, 7, 9, 11, 13 and 15. Select 3 balls and put them into the circles such that the sum of the numbers on them add up to 30.
Hard Riddles
Missing Digit Trick
A professor asked John to write down any multi-digit number. But, he put a condition, the number should not end with a zero.
John put down the number 96452.
Then the professor asked John to add up the five digits and subtract the total from the original number. John did and here is what he got:
96452 – 26 = 96426
The professor then asked John to cross out any one of the five digits and tell him the remaining numbers. John crossed out the 2 and told the professor the rest of the digits. John neither told the professor the original number nor what he had done with it. Yet, the professor told John the exact number he had crossed out.
How is it possible?
Riddle Answer100 Questions 85 Marks
I was given 100 questions to be solved. I scored 85. The score was calculated by subtracting twice the number of wrong answers from number of correct answers. How many questions did I solve correctly?
Riddle Answer28 Handshakes
There was a small get-together. There were a total of 28 handshakes exchanged between the guests. How many guests were present?
Riddle Answer2 Equals 1 Proof
What is wrong with the following proof?
2=1
a = b
a2 = ab
a2 – b2 = ab – b2
(a+b)(a-b) = b(a-b)
a + b = b
2b = b
2 = 1