Practice Logical Statement in Math

Use these practice problems to test your method after reviewing the concept explanation and worked examples.

Quick Recap

A logical statement (or proposition) is a declarative sentence that has exactly one truth value: it is either true or false. For example, '7 is prime' is a logical statement (true), while 'Is 7 prime?' is not (it's a question).

A logical statement is any claim that can be judged definitively as true or false โ€” questions, commands, and paradoxes are not statements.

Showing a random 20 of 50 problems.

Example 1

easy
Is 'Pizza is delicious' a logical statement?

Example 2

medium
Which of these has a truth value: (a) '2\sqrt{2} is irrational', (b) 'Hello!', (c) '3>13 > 1'?

Example 3

easy
True or false: every logical statement is either true or false.

Example 4

challenge
Is 'Pโ†’PP \to P' a logical statement for any statement PP, and what is its truth value?

Example 5

easy
Is the sentence 'Hello!' a logical statement?

Example 6

easy
Is '3<53 < 5 and 5<75 < 7' a logical statement?

Example 7

easy
Is '2+2=52 + 2 = 5' a logical statement?

Example 8

medium
Determine the truth value: 'There exists a real xx with x2=โˆ’1x^2=-1.'

Example 9

medium
Is the sentence 'This statement is false' a logical statement?

Example 10

medium
Classify: (a) 'The set {1,2,3}\{1,2,3\} has three elements.' (b) '2\sqrt{2} is rational.' (c) 'Solve x+1=4x+1=4.'

Example 11

challenge
Given statements PP and QQ, explain why exactly one of 'PP' and 'ยฌP\neg P' is true, and what this principle is called.

Example 12

medium
Negate the statement: 'All prime numbers are odd.'

Example 13

medium
Classify each as a statement or not: (a) '7+3=117 + 3 = 11' (b) 'Is 5 prime?' (c) 'Every square is a rectangle.'

Example 14

easy
Is 'All squares are rectangles' a logical statement?

Example 15

easy
Is 'The Earth is flat' a logical statement?

Example 16

easy
Is '5+5=115+5=11' a logical statement?

Example 17

hard
Negate 'โˆ€xโˆƒy:x+y=0\forall x \exists y: x+y=0.'

Example 18

hard
Negate 'For every integer nn, if nn is prime then nn is odd.'

Example 19

medium
Classify each: (a) 'It is raining', (b) 'What time is it?', (c) 'Do your homework'. Which are logical statements?

Example 20

medium
Write the contrapositive of 'If nn is divisible by 44, then nn is even.'