Issue 18 
Season 7. January 18,2006
18. Boomerang (6+5)
Divide each grid along the gridlines into some “boomerangs” (twolegged fi gures, legs are of the same size and they create 120 degree angle). Each figure must contain exactly one black circle. There must be no free cells after dividing.
 |
 |
Example:
Answer key: write down the number of boomerangs in each row, starting from the top row and working downwards. For the example the answer would be: 1,3,4,6,5,4,3.
 |
 |
 |
Answers:
18a. 2,5,6,7,7,6,5,3,1 or 1,4,6,7,8,7,5,3,1
18b. 2,4,6,8,8,7,5,3,2
19. Balance (7)
We have a 4-armed balance and a supply of stones with weights 1 to 6. We start by placing a stone of weight “1” in one pan of the balance. Then we place a stone of weight “2”, then “3”, and so on. After “6” continue again from “1”. If at any time the weights of opposite pairs of pans (AB and CD or AC and BD) differ by more than 4, the balance breaks. Also, we must place at least one stone each of weights “4” and “5” on pan “A”, and at least one stone of weight “2” on pan “B”. The aim is to balance the scales exactly with the fewest possible stones. The weight of all four pans must become exactly the same.
Answer key: Write down the weight of stones put on pans C and D in order. The answer must look like: 6,5,4; 4,4,4,3.
Answer:
1,3,5,1,3; 4,6,3
