It’s Friday night and alongside a few spices, you have exactly seven ingredients in your kitchen: beer, eggs, instant noodles, ketchup, tomatoes, potato salad, and hot dogs. You aren’t planning to go grocery shopping until Sunday morning, so you have to make breakfast, lunch, and dinner on Saturday with only these ingredients available to you.

For the purpose of this question, a ‘meal’ consists of at least one ingredient. You can use each ingredient exactly once and for exactly one meal — but not all ingredients have to be used on Saturday.

  • Because you want to maintain some semblance of normalcy, the meals must be prepared with the following conditions in mind:
  • The beer and the eggs cannot be used for the same meal.
  • The ketchup and the hot dogs, if both used, must be used for the same meal.
  • If you eat the instant noodles for dinner, you must also eat the tomatoes for dinner.
  • You cannot eat the potato salad for breakfast.
  • Because the ketchup was manufactured in 2013, it is expiring on Sunday and therefore must be used in a meal on Saturday.

1. Which of the following is a meal plan that complies with the above conditions?

a. breakfast: potato salad, eggs

lunch: beer, instant noodles

dinner: ketchup, hot dogs

b. breakfast: beer, eggs

lunch: potato salad, ketchup

dinner: instant noodles, tomatoes

c. breakfast: hot dogs, ketchup, beer

lunch: instant noodles, eggs

dinner: potato salad

d. breakfast: tomatoes, eggs, instant noodles

lunch: hot dogs

dinner: beer, potato salad

e. breakfast: ketchup, eggs

lunch: tomatoes, beer, potato salad

dinner: instant noodles, hot dogs

2. If you eat the instant noodles for dinner and the eggs for breakfast, which of the following can be true? 

a. you drink the beer for breakfast and eat the tomatoes for dinner

b. you eat the tomatoes for lunch and drink the beer for dinner

c. you eat the potato salad for lunch and the tomatoes for breakfast

d. you use exactly one ingredient for dinner

e. you use exactly two ingredients for dinner

3. If you eat the ketchup for lunch and drink the beer for dinner, how many of the other ingredients can be eaten for breakfast? 

a. 2

b. 3

c. 4

d. 5

e. 6

4. If neither hot dogs nor tomatoes are used on Saturday, which of the following cannot be true?

a. you eat the ketchup for lunch

b. you eat the potato salad for lunch

c. you eat the eggs for breakfast

d. you eat the instant noodles for dinner

e. you drink the beer for breakfast

5. Suppose, while you’re out Friday night, that your roommate steals your beer and potato salad for their dinner­ — you’ll yell at them later. All other conditions staying constant, which of the following cannot be true of your meal plan for Saturday? 

a. you eat the eggs for breakfast, and you use exactly one ingredient for dinner

b. you eat the hot dogs for dinner, and you use exactly two ingredients for both  breakfast and lunch

c. you eat the instant noodles for dinner, and you use exactly one ingredient for both breakfast and lunch

d. you eat the ketchup and the hot dogs for breakfast

e. you eat the ketchup and the hot dogs for dinner

 

 

 

 

 

Answer key: 1. c, 2. e, 3. b, 4. d, 5. b