Number Theory
Is 32456 divisible by 3?
No.
Factorize 12xy +18x.
6x (2y+3)
In a right-angled triangle there is always a ........ degree angle.
90
What is the smallest two-digit prime number?
11
Open the brackets:
(x -1)(x+1)
x2 _ 1
How many sides are there in a nonagon?
9
True or False? If a number is divisible by 12, then it is also divisible by 4.
True.
I thought of a number. I added 2, then I multiplied by 3. Then I subtracted 1 and I got 20. Which number did I think of?
5
What is the sum of the exterior angles in a triangle?
360
What is the greatest common divisor of 18 and 27?
9
2(x - 1) + 3 (2 - x) = 9
-5
Calculate the area of circle whose radius is 10 cm.
314 cm2
What is the lowest common multiple of 10 and 15?
30
In a family a father alone can dig their whole garden in 1 hour. His wife can do it in 2 hours. How much time is needed if they work together?
40 minutes
In a right-angled triangle the two shorter sides are 5 cm and 12 cm. Calculate the longest side.
13