快猫短视频

#197 Marshmallow test

Set by Zoe Mensch

We bought some marshmallows to toast on the fire, but my daughter had other ideas. She started building shapes by joining marshmallows together with cocktail sticks.

In one effort, she put four marshmallows on the table and, keeping them on the surface, joined them with six cocktail sticks, as shown here. To do this, she had to break three of the sticks to the same shorter length (shown by the dotted lines).

鈥淰ery neat,鈥� I thought, 鈥渢hough she wouldn鈥檛 have had to shorten any sticks if she鈥檇 arranged them as a pyramid.鈥�

A few minutes later, she came up with a different way of joining four marshmallows to each other using a fresh batch of six sticks. Again, the marshmallows were flat on the table and three of the sticks were full length, while the other three had been shortened. As before, the three shortened sticks were the same length as each other.

Can you find her other arrangement?

Solution next week

#196 Champion trainer

Solution

The winning horse in the race was trained by Harry Trotter.

The total number of points awarded are 9 + 8 + 7 + 鈥� + 1, which equals 45, so the trainers each got 15 points. The only combinations of points totalling 15 are 951, 942, 861, 852, 843, 762, 753 and 654. Kate had two consecutively placed horses with another finishing behind them, so her points could only be 7-6-2 or 6-5-4. Harry got 1 point for the last horse, so his must be 9-5-1 or 8-6-1, but we know that one of Kate鈥檚 got 6 points, meaning his scores were 9-5-1 and he trained the winning horse. The points awarded to Kate were 7-6-2 and Britney 8-4-3.