7 + 8 = ?
Answer : 15
7 + 8 = 15.
Questions and answers: Mathematics
Revise Mathematics: here is a selection of questions of every level, with the answer and an explanation. To test yourself without seeing the answers, play the quizzes.
Play the Mathematics quizzesVery easy
6 × 7 = ?
Answer : 42
6 × 7 = 42.
How many sides does a triangle have?
Answer : 3
A triangle has three sides.
What is half of 50?
Answer : 25
50 ÷ 2 = 25.
100 − 37 = ?
Answer : 63
100 − 37 = 63.
How many degrees is a right angle?
Answer : 90
A right angle measures 90 degrees.
9 × 9 = ?
Answer : 81
9 × 9 = 81.
Which of these numbers is even?
Answer : 14
14 = 2 × 7.
Easy
What is the perimeter of a square with side 5?
Answer : 20
4 × 5 = 20.
What is 2 to the power of 5?
Answer : 32
2 × 2 × 2 × 2 × 2 = 32.
What is the sum of the angles of a triangle?
Answer : 180°
The sum is always 180 degrees.
What is the square root of 144?
Answer : 12
12 × 12 = 144.
Which of these numbers is prime?
Answer : 13
13 is divisible only by 1 and itself.
What is 25% of 200?
Answer : 50
200 ÷ 4 = 50.
How many sides does a hexagon have?
Answer : 6
Hexa means six in Greek.
What is 3/4 written as a decimal?
Answer : 0.75
3 ÷ 4 = 0.75.
Medium
What is the approximate value of pi?
Answer : 3.14
Pi is about 3.14159.
Solve 2x + 6 = 20: what is x?
Answer : 7
2x = 14, x = 7.
What is the area of a circle of radius 3?
Answer : 9π
π × 3² = 9π.
What is 5! (5 factorial)?
Answer : 120
5 × 4 × 3 × 2 × 1 = 120.
In a right triangle with legs 3 and 4, what is the hypotenuse?
Answer : 5
√(3² + 4²) = √25 = 5.
Which Greek scholar gives his name to a famous theorem about right triangles?
Answer : Pythagoras
It is the Pythagorean theorem.
What is the median of the series 3, 7, 9, 12, 20?
Answer : 9
The middle value is 9.
2^10 = ?
Answer : 1024
2^10 = 1024.
Hard
What is the derivative of x²?
Answer : 2x
(x²)' = 2x.
log₁₀(1000) = ?
Answer : 3
10³ = 1000.
What is the sum of the integers from 1 to 100?
Answer : 5050
100 × 101 ÷ 2 = 5050.
How many diagonals does a hexagon have?
Answer : 9
n(n − 3)/2 = 6 × 3 / 2 = 9.
In Euler's identity, what is e^(iπ) + 1?
Answer : 0
e^(iπ) = −1 ⇒ e^(iπ) + 1 = 0.
What is the probability of getting two heads when flipping two fair coins?
Answer : 1/4
1/2 × 1/2 = 1/4.
What are the solutions of x² − 5x + 6 = 0?
Answer : 2 and 3
(x − 2)(x − 3) = 0.
How many edges does a cube have?
Answer : 12
A cube has 12 edges, 8 vertices and 6 faces.
Expert
Which mathematician proved Fermat's Last Theorem?
Answer : Andrew Wiles
Andrew Wiles proved it in 1994-1995.
Who proved the Poincaré conjecture?
Answer : Grigori Perelman
Perelman proved it in the early 2000s.
How many Platonic solids are there?
Answer : 5
Tetrahedron, cube, octahedron, dodecahedron, icosahedron.
For a convex polyhedron, what is V − E + F (vertices − edges + faces)?
Answer : 2
This is the Euler characteristic.
What is the exact expression of the golden ratio?
Answer : (1 + √5) / 2
φ = (1 + √5) / 2 ≈ 1.618.
For which results is Kurt Gödel famous?
Answer : The incompleteness theorems
He published them in 1931.
The Riemann hypothesis concerns the zeros of which function?
Answer : The Riemann zeta function
It concerns the non-trivial zeros of the zeta function.
What is the determinant of the matrix [[1, 2], [3, 4]]?
Answer : −2
1 × 4 − 2 × 3 = −2.