Durofy » Mathematics

Brain Teaser - Chameleons

Rishabh Dev — Mon, 24 Oct 2011 04:57:48 +0000

On an island live 13 purple, 15 yellow and 17 maroon chameleons. When two chameleons of different colors meet, they both change into the third color. Is there a sequence of pairwise meetings after which all chameleons would have the same color?

Math Puzzle : Find the remainder

Rishabh Dev — Tue, 11 Oct 2011 04:09:37 +0000

If x = (16^³+ 18^³ + 19^³), then find the remainder if x divided by 70.

a. 0
b. 1
c. 69
d. 35

Math Puzzle - Sum of multiples

Rishabh Dev — Tue, 11 Oct 2011 04:08:31 +0000

If we list all the natural numbers below 10 that are multiples of 3 or 5, we get 3, 5, 6 and 9. The sum of these multiples is 23. Find the sum of all the multiples of 3 or 5 below 1000.

Brain Teaser - 12 or 13 Men

Rishabh Dev — Thu, 01 Sep 2011 15:10:57 +0000

Found this interesting puzzle on wired(.com). Can you explain it?

(wait for it to change)

How many men are there? 12 or 13? Can you figure out how it works?

Math Puzzle - Possible chess games

Rishabh Dev — Thu, 01 Sep 2011 15:07:10 +0000

How many chess games are possible? Yeah. All the possible games that could be played on the chess board. ever. How many are those?

Brain Teaser - Find the heavy ball

Rishabh Dev — Tue, 30 Aug 2011 17:51:34 +0000

You have 5565 balls. One of them is heavier than the others. What is the minimum number of weighs required to find this ball?

Math Puzzle - Find the next number

Rishabh Dev — Mon, 29 Aug 2011 19:46:34 +0000

8, 15, 27, 51, ?

Math Puzzle - Time, Work & Payments

Rishabh Dev — Mon, 29 Aug 2011 12:53:14 +0000

A alone can do a piece of work in 6 days and B alone in 8 days. A and B undertook to do it for Rs. 3200. With the help of C, they completed the work in 3 days. How much is to be paid to C?

Math Puzzle - Make a Magic Square

Rishabh Dev — Sun, 28 Aug 2011 13:09:25 +0000

Question - Make a magic square with nine consecutive composite numbers—the smallest possible.

"A magic square of order n is an arrangement of n2 numbers, usually distinct integers, in a square, such that the n numbers in all rows, all columns, and both diagonals sum to the same constant." - Wikipedia

Eg:

Math Puzzle - Timpkinses Ages Problem

Rishabh Dev — Sun, 28 Aug 2011 12:32:14 +0000

Edwin: "Do you know, when the Timpkinses married eighteen years ago Timpkins was three times as old as his wife, and to-day he is just twice as old as she?"

Angelina: "Then how old was Mrs. Timpkins on the wedding day?"

Can you answer Angelina's question?