Puzzle 19: School Sister
In Puzzle 19, there are two sisters who walk to school in the morning. The younger sister leaves the house and walks 1 meter per second. The Older sister waits until the younger sister has walked 100 meters, then she walks to school at 2 meters per second. What is the minimum number of seconds that it could take for the older sister to catch up to the younger sister. Assume neither of them turn around for any reason.
At first, you might be tempted to do a lot of dividing to figure this one out, but it turns out that this puzzle is much simpler than you might expect. Since this puzzle is asking for the minimum time possible, we can consider the possibility of the younger sister stopping at 100 meters. It would therefore take the older sister 50 seconds (100 meters divided by 2 meters per second) to get to the younger sister.
The game itself offers the possibility of the school itself sitting only 100 meters away from the girls’ house.
Puzzle 20: In the Spotlight
Puzzle 20 is a nice break from these riddles. It’s a simple visual puzzle. There are spotlights on the sides of a grid, and mirrors inside the grid itself. Our goal is to use exactly 4 spotlights to light up the entire grid.
We can light it up by turning on the first and sixth spotlights (from the top) on the left side of the grid and the second and fourth spotlights (from the top) on the right side.
Puzzle 21: A Stellar Display
Puzzle 21 gives us two different stars. We need to arrange them so that we make five circles out of them. We can move, rotate, and even grow or shrink the stars.
To make five circles, grow the flower-shaped star once, then rotate it once. Finally, move it over the pointy-shaped star so that the points align with the inside points of the flower star.