Today's PUZZLE CLASSIC OF THE DAY

Place digits 1 through 9 in three rows in order to get three 3-digits numbers, so that the 2nd row number is twice bigger than the top one, and the bottom row number - thrice bigger than the top one.

What number should go instead of the question mark to complete the sequence?

It is possible to get 100 by placing two arithmetic signs somewhere between these four sevens. What are the signs and where they should go?

How many triangles are in this figure? Select a triangle and click the "Count" button.

How many triangles are in this figure? Select a triangle and click the "Count" button.

Place the numbers from 1 through 11 in the circles so that the numbers in every 3 circles on a straight line total 18.

Place digits 1-9 into the spots so that the entire math expression shown here is correct.

Digits 1-9, when added together, produce 45. By replacing one plus with another arithmetic sign, it is possible to get 100. Which plus and with what sign must be replaced?

When Black Bart took the Denver stagecoach for the 13th time, his luck finally ran out. The only cash he found was in the merchant's travel bag, and it was $5, all in coins. There were exactly 100 coins, though not a single nickel or quarter. Can you determine their quantities?

You must boil an egg for exactly 5 mins. All you have is a 3-min and a 4-min hourglasses. How many times will you need to turn each hourglass in order to measure 5 mins?

How many triangles are in this figure? Select a triangle and click the "Count" button.

How many triangles are in this figure? Select a triangle and click the "Count" button.