Solution:

Warm Up

Solution:

20 times

8,18,28,38,48,58,68,78,98,80,81,82,83,84,85,86,87,88,88(2),89

Solution:

From left to right: the jack of clubs, jack of diamonds, and queen of diamonds.

OR: jack of diamonds, jack of clubs, queen of diamonds.

Solution:

In vacuum both will reach in same time.

whereas in case of air density medium it will depend on the surface area which is exposed to gravity opposing force.
gravity opposing force will increase as it is coming downwards and the amount of force is directly proportional to the area exposed to it.

Solution:

Forty.

The number of decks is irrelevant; the answer is the same if one or one-hundred decks are used.

Any card drawn will be a A,2,3,4,5,6,7,8,9,10,J,Q, or K, so there are 13 possibilities each time a card is drawn.

The fastest way to draw a four of a kind is if the first four cards all have the same 'value.' The slowest way, which provides the solution, is to first draw 13 three of a kinds, and then one more card.

Since 13 x 3 + 1 = 40, if 40 cards are drawn it is guaranteed that those forty cards contain at least one four of a kind.

Solution:

They all read the same rightside or upside down.

Solution:

Tilt the Mug until the coke barely touches the lip of the Mug. If the bottom of the Mug is visible then it is less than half full. If the Mug bottom is still completly coverd by the coke, then it is more than half full.

Solution:

Because she wanted to see the butterfly (butter+fly)

Solution:

The digits are 12, 5, 6, and 8

Solution:

Books