Julie says to her brother Pete: “I have as many sisters as brothers.”

“Yeah, well,” replies Pete: “I’ve got twice as many sisters as I have brothers.”

How many sisters and brothers are there?

Riddle AnswerJulie says to her brother Pete: “I have as many sisters as brothers.”

“Yeah, well,” replies Pete: “I’ve got twice as many sisters as I have brothers.”

How many sisters and brothers are there?

Riddle AnswerYou have unlimited supply of 1¢, 5¢, 10¢, 25¢ and 50¢ (penny, nickel, dime, quarter, half-dollar respectively) coins. What is the fewest number of coins required to have an exact change for all possible items that cost from one cent up to and including one dollar in one-cent increments?

Riddle AnswerThere are two brothers whose combined age is eleven years. One is ten years older than the other. What are their ages?

Answer

They are 10.5 and 0.5 years old.

A common wrong answer is 10 and 1. This is wrong because the difference in age would be 9, not 10.

Ben and Mark are students of Mr Tan. Mr Tan’s date of birth is on N/M/1970 and both of them know that Mr Tan’s birthday is one of these 10 dates:

4/3/1970 5/3/1970 8/3/1970 4/6/1970 7/6/1970 1/9/1970 5/9/1970 1/12/1970 2/12/1970 8/12/1970

Mr Tan tells Ben the value of M and tells Mark the value of N. Then Mr Tan asks them: “Do you know when my birthday is?”

Ben says: “I don’t know, but I can be sure that Mark doesn’t know either.”

Mark says: “Initially I don’t know, but now I do.”

Ben says: “Oh, then now I know it too.”

Based on this dialogue and the dates given, can you figure out which is the correct date of Mr Tan’s birthday?

Riddle Answer