Grade 11 Logic Puzzles Worksheet

Grade 11 Logic Puzzles

Read each logic puzzle carefully and use your reasoning skills to solve them. Show your work or explain your reasoning where applicable.

1. You are in a room with three light switches. In an adjacent room, there are three light bulbs. You cannot see the light bulbs from the room with the switches. You can only enter the room with the light bulbs once. How can you determine which switch controls which bulb?

2. A farmer needs to cross a river with a fox, a chicken, and a bag of grain. The boat can only carry the farmer and one other item at a time. If left alone, the fox will eat the chicken, and the chicken will eat the grain. How can the farmer get all three across the river safely?

First, the farmer takes the   across. The farmer returns alone. Then, the farmer takes the   across. The farmer brings the   back. Next, the farmer takes the   across. Finally, the farmer returns alone to get the  .

3. On an island, there are two types of people: Knights, who always tell the truth, and Knaves, who always lie. You meet two islanders, A and B. A says, "B is a Knight." B says, "A and I are of opposite types." What are A and B?

4. Consider the statement: "This statement is false." Is this statement true or false?

5. You have 9 coins, and one of them is heavier than the others. You have a balance scale. What is the minimum number of weighings needed to find the heavier coin? Explain your strategy.