Today's PUZZLE CLASSIC OF THE DAY

Place the digits 1-9 in this circle so that every straight line across the wheel adds up to 15. Digit 7 is already placed in the wheel.

Place the digits 1 to 8 into the vertices of a cube so that the sum of the digits on each cube's face is the same.

Arrange digits 1 through 9 along the sides of the triangle so that the numbers along each side add up to 20.

Digits 1, 2, and 3 are placed in the vertices of the equilateral triangle. Add digits 4-9 along the sides of the triangle so that the digits' sum on each side is 17.

A sphere fits exactly inside a thin-walled cylinder that has a height and the diameter equal to the diameter of the sphere. Let's mark the surface area of the sphere as SA(s) and the lateral surface area (which is EXCLUDING the bases) of the cylinder as LSA(c). How SA(s) is related to LSA(c)?

Place the digits 1 through 7 in the grid so that the total in the circles along each indicated line is the same. What is that total?

Place the digits 1-7 into seven intersections so that the sums on the big circumference, the small circumference, and each straight segment are all 12. HINT: think what digit should go into the center.

What three numbers have their sum equal to their product?

Find a number less than 100 that is increased by one-fifth of its value (+20%) when its digits are reversed.

When 8 + 8 = 4 is true?

In the plant’s turning shop the final parts are turned from lead billets. A part from one billet. The shaved off chips obtained after 6 parts are produced, can then be melted into an additional billet. How many final parts can be made in this way from the initial 36 lead billets?

What number should be placed in the lower right cell to complete the entire square logically? Please, drag and drop the numbers from other cells to get your answer there.