Logical reasoning in daily decisions in Intro to Computing - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Understanding Logical Conditions in Daily Choices

Imagine you decide whether to carry an umbrella based on the weather forecast. The rule is: "If it is raining or if the forecast predicts rain, then carry an umbrella." Which logical condition best represents this decision?

A Carry umbrella if raining OR forecast predicts rain

B Carry umbrella if raining AND forecast predicts rain

C Carry umbrella only if raining but not if forecast predicts rain

D Carry umbrella only if forecast predicts rain AND it is not raining

💡 Hint

Think about when you want to be prepared: either actual rain or a prediction of rain.

The decision uses an OR condition because carrying an umbrella is needed if either it is raining or rain is predicted. Using AND would require both conditions to be true, which is too restrictive.

❓ trace

intermediate

Tracing a Decision Flowchart for Morning Routine

Consider this flowchart for deciding whether to take a jacket:

1. Is it cold outside? (Yes/No)
2. If Yes, take a jacket.
3. If No, check if it might rain.
4. If it might rain, take a jacket.
5. If not, do not take a jacket.

If it is not cold but rain is predicted, what is the final decision?

A Take a jacket

B Take a raincoat instead of a jacket

C Decision cannot be made

D Do not take a jacket

💡 Hint

Follow the flowchart steps carefully for the given conditions.

Since it is not cold, the flow moves to check rain prediction. Because rain is predicted, the decision is to take a jacket.

❓ Comparison

advanced

Comparing Logical Operators in Decision Making

You want to decide if you should go for a walk. The conditions are: "Go for a walk if it is sunny AND you have free time." Which of the following statements correctly compares the AND and OR operators in this context?

A AND requires only one condition true; OR requires both conditions true

B AND requires both conditions true; OR requires only one condition true

C AND and OR both require both conditions true

D AND and OR both require only one condition true

💡 Hint

Recall the difference between AND and OR in logic.

AND means both conditions must be true to proceed; OR means either condition being true is enough.

❓ identification

advanced

Identifying Logical Errors in a Daily Decision Scenario

John decides: "If I am hungry or if it is lunchtime, I will eat." He writes the condition as: "If hungry AND lunchtime, then eat." What is the logical error in John's condition?

A He used OR instead of AND, making the condition too strict

B There is no error; the condition is correct

C He should use NOT operator instead of AND

D He used AND instead of OR, making the condition too strict

💡 Hint

Think about when John wants to eat: if hungry or if it is lunchtime.

Using AND means John will eat only if both hungry and lunchtime are true, but he wants to eat if either is true, so OR is correct.

🚀 Application

expert

Applying Logical Reasoning to Plan a Weekend Activity

You plan your weekend activity based on these rules:

• If it is sunny and you have no work, go hiking.
• If it is rainy or you have work, stay home and read.
• If it is sunny but you have work, go for a short walk.

Given it is sunny and you have work, what activity should you choose?

A Go hiking

B Stay home and read

C Go for a short walk

D No activity planned

💡 Hint

Check each rule carefully and see which applies to the given conditions.

Since it is sunny and you have work, the third rule applies: go for a short walk.

Practice

1. Which of the following best describes logical reasoning in daily decisions?

easy

A. Doing the opposite of what is suggested

B. Making choices step-by-step using IF-THEN-ELSE thinking

C. Ignoring all options and guessing

D. Choosing randomly without thinking

Solution

1. Step 1: Understand logical reasoning

   Logical reasoning means making decisions by checking conditions step-by-step, like asking "If this, then that".

2. Step 2: Compare options

   Making choices step-by-step using IF-THEN-ELSE thinking clearly explains this step-by-step IF-THEN-ELSE thinking, while others describe random or opposite actions.

3. Final Answer:

   Making choices step-by-step using IF-THEN-ELSE thinking -> Option B

4. Quick Check:

   Logical reasoning = step-by-step IF-THEN-ELSE [OK]

Hint: Look for step-by-step decision making [OK]

Common Mistakes:

• Confusing logical reasoning with guessing
• Ignoring the IF-THEN-ELSE structure
• Thinking random choice is logical reasoning

2. Which of these is the correct way to express a simple decision in programming logic?

easy

A. do_something if condition else do_something_else

B. if condition then do_something else do_something_else

C. if do_something then condition else do_something_else

D. condition if do_something else do_something_else

Solution

1. Step 1: Identify correct IF-THEN-ELSE syntax

   In many programming languages like Python, the correct syntax for a simple decision expression is: do_something if condition else do_something_else.

2. Step 2: Check each option

   do_something if condition else do_something_else matches the correct syntax used in Python. if condition then do_something else do_something_else uses 'then' which is not valid syntax in Python. Options C and D mix order incorrectly.

3. Final Answer:

   do_something if condition else do_something_else -> Option A

4. Quick Check:

   Python conditional expression syntax = do_something if condition else do_something_else [OK]

Hint: Remember Python's conditional expression: action if condition else alternative [OK]

Common Mistakes:

• Using 'then' keyword in Python
• Swapping condition and action order
• Mixing condition with actions

3. Consider this flowchart for deciding whether to take an umbrella:

What is the correct decision if it is raining?

medium

A. Wait and see

B. Don't take an umbrella

C. Take an umbrella

D. Call a friend

Solution

1. Step 1: Analyze the flowchart condition

   The flowchart asks: "Is it raining?" If yes, the arrow points to "Take umbrella".

2. Step 2: Follow the decision path for 'Yes'

   Since it is raining, the decision is to take an umbrella.

3. Final Answer:

   Take an umbrella -> Option C

4. Quick Check:

   Raining? Yes -> Take umbrella [OK]

Hint: Follow the 'Yes' path for raining [OK]

Common Mistakes:

• Choosing the 'No' path by mistake
• Ignoring the flowchart arrows
• Overthinking the simple question

4. You have this decision logic:

if hungry:
    eat()
else:
    wait()

But the code gives an error. What is the most likely problem?

medium

A. The else statement should come before if

B. The functions eat() and wait() are spelled wrong

C. The colon ':' is missing after if and else

D. The condition 'hungry' is not defined or missing value

Solution

1. Step 1: Check the condition variable

   The condition 'hungry' must be defined as True or False before use; otherwise, it causes an error.

2. Step 2: Review other syntax elements

   Functions and colons look correct; else cannot come before if.

3. Final Answer:

   The condition 'hungry' is not defined or missing value -> Option D

4. Quick Check:

   Undefined condition causes error [OK]

Hint: Ensure condition variables are defined before use [OK]

Common Mistakes:

• Assuming function names cause error
• Thinking else can come before if
• Missing colons (not the main error here)

5. You want to decide what to wear based on weather:

if temperature < 10:
    wear('coat')
elif temperature < 20:
    wear('jacket')
else:
    wear('t-shirt')

If the temperature is 15, what will you wear?

hard

A. jacket

B. coat

C. t-shirt

D. nothing

Solution

1. Step 1: Check temperature against first condition

   15 is not less than 10, so skip the first if block.

2. Step 2: Check temperature against elif condition

   15 is less than 20, so wear('jacket') is executed.

3. Final Answer:

   jacket -> Option A

4. Quick Check:

   15 < 20 but >= 10 means jacket [OK]

Hint: Check conditions top to bottom until one matches [OK]

Common Mistakes:

• Choosing coat because 15 is close to 10
• Choosing t-shirt ignoring elif
• Not understanding elif means else if