Numeric values (int and float behavior) in Python - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of mixed int and float arithmetic

What is the output of this Python code?

Python

result = 5 + 3.0 * 2
print(result)

A 16.0

B 11

C 16

D 11.0

💡 Hint

Remember that multiplying an int by a float results in a float.

Due to operator precedence, 3.0 * 2 = 6.0 (float), then 5 + 6.0 = 11.0.

❓ Predict Output

intermediate

Integer division vs float division

What is the output of this code snippet?

Python

a = 7 // 2
b = 7 / 2
print(a, b)

A 3 3.5

B 3.5 3

C 3 3

D 3.5 3.5

💡 Hint

// is floor division, / is true division.

7 // 2 is 3 (integer floor division), 7 / 2 is 3.5 (float division).

❓ Predict Output

advanced

Float precision in arithmetic

What is the output of this code?

Python

x = 0.1 + 0.2
print(x == 0.3)

A True

B TypeError

C False

D SyntaxError

💡 Hint

Floating point numbers can have small precision errors.

0.1 + 0.2 is not exactly 0.3 due to floating point precision, so the comparison is False.

❓ Predict Output

advanced

Type and value after mixed operations

What is the type and value of variable 'result' after running this code?

Python

result = int(4.7) + float(3)

A <class 'float'> and 7

B <class 'int'> and 7.0

C <class 'int'> and 7

D <class 'float'> and 7.0

💡 Hint

int(4.7) converts 4.7 to 4, float(3) converts 3 to 3.0.

int(4.7) is 4 (int), float(3) is 3.0 (float), 4 + 3.0 is 7.0 (float).

🧠 Conceptual

expert

Behavior of float('inf') in arithmetic

Which option correctly describes the output of this code?

Python

import math
x = float('inf')
y = x - 1000
print(y == x)

A False

B True

C Raises OverflowError

D Raises ValueError

💡 Hint

Infinity minus any finite number is still infinity.

float('inf') represents positive infinity; subtracting a finite number does not change it, so y == x is True.

Practice

1.

Which of the following is an example of a float in Python?

1. 42
2. 3.14
3. -7
4. 0

easy

A. 42

B. 3.14

C. -7

D. 0

Solution

1. Step 1: Understand what a float is

   A float is a number with a decimal point, like 3.14.

2. Step 2: Identify the float among options

   Only 3.14 has a decimal point, so it is a float.

3. Final Answer:

   3.14 -> Option B

4. Quick Check:

   Float = 3.14 [OK]

Hint: Floats always have a decimal point [OK]

Common Mistakes:

• Choosing integers as floats
• Confusing negative numbers with floats
• Ignoring decimal points

2.

Which of the following is the correct way to convert the float 5.7 to an integer in Python?

easy

A. float(5.7)

B. int(5,7)

C. int('5.7')

D. int(5.7)

Solution

1. Step 1: Recall how to convert float to int

   Use the int() function with a float value as argument.

2. Step 2: Check each option

   int(5.7) correctly converts float 5.7 to int 5. int('5.7') causes error, int(5,7) is invalid syntax.

3. Final Answer:

   int(5.7) -> Option D

4. Quick Check:

   int(5.7) = 5 [OK]

Hint: Use int() directly on float to convert [OK]

Common Mistakes:

• Trying int() on string with decimal
• Using wrong syntax like int(5,7)
• Using float() instead of int()

3.

What is the output of the following code?

x = 7 / 2
print(type(x))
print(x)

medium

A. <class 'int'>\n3.5

B. <class 'int'>\n3

C. <class 'float'>\n3.5

D. SyntaxError

Solution

1. Step 1: Understand division operator in Python 3

   Division with / always returns a float, even if numbers divide evenly.

2. Step 2: Evaluate the code

   7 / 2 = 3.5, which is a float. So type(x) is <class 'float'> and x is 3.5.

3. Final Answer:

   <class 'float'>\n3.5 -> Option C

4. Quick Check:

   7 / 2 = 3.5 float [OK]

Hint: Division / always returns float in Python 3 [OK]

Common Mistakes:

• Assuming integer division with /
• Confusing type output format
• Expecting 3 instead of 3.5

4.

Find the error in this code snippet:

num = 4.8
num_int = int(num)
print(num_int + ' is the integer value')

medium

A. Cannot add int and str directly

B. No error, code runs fine

C. Syntax error in print statement

D. Cannot convert float to int

Solution

1. Step 1: Check conversion from float to int

   int(4.8) converts float 4.8 to int 4 without error.

2. Step 2: Check print statement

   Adding int and string directly causes a TypeError in Python.

3. Final Answer:

   Cannot add int and str directly -> Option A

4. Quick Check:

   int + str causes TypeError [OK]

Hint: Convert int to str before adding to string [OK]

Common Mistakes:

• Thinking int() conversion fails
• Ignoring type mismatch in addition
• Assuming print syntax error

5.

You have a list of mixed numbers: nums = [1, 2.5, 3, 4.75, 5]. You want to create a new list with all numbers converted to integers by dropping decimals. Which code correctly does this?

hard

A. new_nums = [int(n) for n in nums]

B. new_nums = [float(n) for n in nums]

C. new_nums = [str(int(n)) for n in nums]

D. new_nums = [round(n) for n in nums]

Solution

1. Step 1: Understand the goal

   We want to convert all numbers to int by dropping decimals, not rounding.

2. Step 2: Evaluate each option

   C uses int() which drops decimals correctly. A converts to string, not int. B converts to float, not int. D rounds numbers, which changes values.

3. Final Answer:

   new_nums = [int(n) for n in nums] -> Option A

4. Quick Check:

   int() drops decimals, list comprehension applies to all [OK]

Hint: Use int() in list comprehension to drop decimals [OK]

Common Mistakes:

• Using round() instead of int()
• Converting to string instead of int
• Using float() which keeps decimals