If a cork is placed into a glass of water, it will almost always drift to the side of the glass. There is one simple way, however, to get the cork to float in the center of the glass. What is it?
Water, the glass, and the cork are all that is required.
The reason that a cork drifts to the side of a glass is that it floats to the highest point. Since water “clings” to the glass, the highest point is around the edge of the water. To get the cork to float in the middle of the glass, all you have to do is fill the glass as much as possible. The water will form a convex shape above the glass, with the highest point at its center. This is where the cork will settle.
Ten seconds is 1/6 of a minute and 1 minute is 1/60 of an hour, so 10 seconds is 1/360 of an hour.
If you graph her trip with the speed on the y-axis and the time on the x-axis, you get a triangle with height of 60 mph and width of 1/360 of an hour. To calculate the area of the triangle, you multiply 1/2 × 1/360 × 60 = 1/12.
Pawns in a chess game. There are eight pawns and they are only permitted to move forward, not backward and the primary objective in chess is to protect the king.
Franklin lent Darlene as much money as she already had, then she spent $10. The next day, Franklin lent her as much money as she now had and again, she spent $10. On the third day Franklin once again lent her as much money as she now had and she spent $10, leaving her broke. How much money did Darlene start with?
$8.75 You may have been tempted to guess $30 because $10 is spent three times, but that would mean she would have had $60 ($30 lent plus the $30 she already had), and $50 after spending $10. The rest of the numbers end up at higher than zero, so we know it has to be less than $30. Even starting at $10 leaves Darlene with $10 on the third day. Starting with $8.75 works out as follows.
