Register
Login
Username
Password
Login
forgot your password?
Home
Forum
^{+0}
Formulary
Maths
Help
Complex Numbers
Integral Calculus
Differential Calculus
Equations
Graphs
Linear Algebra
Number theory
Percent
Standard Functions
Statistics
Trigonometry
Unit Conversion
Units
About
Imprint
Privacy Policy
Terms of Service
Credits
Google+
Facebook
Contact Email
Post New Question
All Questions
^{+0}
233551 Questions
0
1
1
+721
Number Theory
How many numbers between $1000$ and $2000$ leave a remainder of $3$ when divided by $47?$
●
bingboy
Jun 20, 2024
0
3
3
+721
Number Theory
For a positive integer n, \phi(n) denotes the number of positive integers less than or equal to $n$ that are relatively prime to $n$. What is $\phi(2835)$?
NotThatSmart
●
●
●
bingboy
Jun 20, 2024
0
2
1
+721
Number Theory
Fill in the blanks with three distinct positive integers.
1/___ + 1/___ + 1/___ = \frac{13}{12}
NotThatSmart
●
bingboy
Jun 20, 2024
-1
3
1
+1420
Geometry
The number of diagonals in a certain regular polygon is equal to $2$ times the number of sides. How many sides does this polygon have?
NotThatSmart
●
ABJeIIy
Jun 20, 2024
-1
6
0
+1420
Geometry
Let $IJKLMN$ be a hexagon with side lengths $IJ = LM = 3,$ $JK = MN = 3,$ and $KL = NI = 3$. Also, all the interior angles of the hexagon are equal. Find the area of hexagon $IJKLMN$.
ABJeIIy
Jun 20, 2024
-1
2
1
+1420
Geometry
In the diagram below, each side of convex quadrilateral $ABCD$ is trisected. (For example, $AP = PQ = QB.$) The area of convex quadrilateral $ABCD$ is $180.$ Find the area of the shaded region.
read more ..
NotThatSmart
●
ABJeIIy
Jun 20, 2024
-1
4
0
+1420
Polygons
Let $B,$ $A,$ and $D$ be three consecutive vertices of a regular $20$-gon. A regular heptagon is constructed on $\overline{AB},$ with a vertex $C$ next to $A.$ Find $\angle BAD,$ in degrees.
ABJeIIy
Jun 20, 2024
0
2
1
+1981
Number Theory
The sum of the reciprocals of three positive integers is $\frac{13}{12}$. What are the three positive integers?
●
LiIIiam0216
Jun 20, 2024
0
3
2
+1981
Number Theory
For a positive integer n, \phi(n) denotes the number of positive integers less than or equal to $n$ that are relatively prime to $n$. What is $\phi(20)$?
●
●
LiIIiam0216
Jun 20, 2024
0
2
5
+1981
help me
Starting at the same time, Bill rings a bell every $36$ seconds, and Wendy blows a whistle every $90$ seconds, and Sam blows a horn every $385$ seconds. How many minutes will it be before both Bill and Wendy and Sam simultaneously make a sound?</
read more ..
●
●
●
●
●
LiIIiam0216
Jun 20, 2024
-1
4
1
+153
Counting
A standard six-sided die is rolled $7$ times. You are told that among the rolls, there was one $1,$ one $2$, one $3$, one $4$, one $5$, and two $6$s. How many possible sequences of rolls could there have been? (For example, 2, 3,
read more ..
NotThatSmart
●
BRAlNBOLT
Jun 20, 2024
-3
3
1
+153
Counting
At a meeting, four scientists, two mathematicians, and a journalist are to be seated around a circular table. How many different arrangements are possible if the mathematicians must sit next to each other? (Two seatings are considered equivalent if
read more ..
●
BRAlNBOLT
Jun 20, 2024
-1
4
1
+153
Counting
Four children and four adults are to be seated at a circular table. In how many different ways can they be seated if all the children are next to each other, and all the adults are next to each other? (Two seatings are considered the same if
read more ..
NotThatSmart
●
BRAlNBOLT
Jun 20, 2024
0
3
1
+1981
Geometry
Donatello starts with a marble cube. He then slices a pyramid off each corner, so that in the resulting polyhedron, all the edges have the same side length. If the side length of the original cube is $6$, then find the volume of the resulting
read more ..
●
LiIIiam0216
Jun 20, 2024
0
2
1
+1981
Geometry
In square ABCD, P is on BC such that BP = 5 and PC = 2, and Q is on CD such that DQ = 4 and QC = 3. Find sin angle PAQ.
●
LiIIiam0216
Jun 20, 2024
0
3
3
+713
Algebra
Find the discriminant of the quadratic 5x^2 - 2x + 8 - 2x^2 + 6x + 2 - 2x^2 + 4x - 1.
NotThatSmart
●
●
●
Hi6942O
Jun 20, 2024
0
4
1
+713
Algebra
Find the largest integer $k$ such that the equation
5x^2 - kx + 8 - 20x^2 + 45 = 0
has no real solutions.
●
Hi6942O
Jun 20, 2024
0
5
1
+713
Algebra
All members of our painting team paint at the same rate. If $10$ members can paint a $100$ square foot wall in $10$ minutes, then how long would it take the $15$ members to paint a $100$ square foot wall, in minutes?
●
Hi6942O
Jun 20, 2024
0
1
1
+713
Algebra
All members of our painting team paint at the same rate. If $10$ members can paint a $1000$ square foot wall in $10$ minutes, then how long would it take for $5$ members to paint a $1000$ square foot wall, in minutes?
●
Hi6942O
Jun 20, 2024
0
4
0
+713
Algebra
In physics, Ohm's law says that current through a wire, $I$, is directly proportional to voltage, $V$, and inversely proportional to resistance, $R$:
I = V/R
It's also true that resistance is directly proportional to the length of the wire.
read more ..
Hi6942O
Jun 20, 2024
0
4
1
+713
Algebra
A plane flies from Penthaven to Jackson and then back to Penthaven. When there is no wind, the round trip takes $3$ hours and $20$ minutes, but when there is a wind blowing from Penthaven to Jackson at $70$ miles per hour, the trip takes $3$ hours
read more ..
●
Hi6942O
Jun 20, 2024
0
3
1
+1981
Number Theory
How many numbers between $1000$ and $2000$ leave a remainder of $3$ when divided by $21?$
Tottenham10
●
LiIIiam0216
Jun 20, 2024
Jun 19, 2024
0
2
1
+713
Algebra
Find all ordered pairs x, y of real numbers such that x+y=10 and x^2+y^2=64.
For example, to enter the solutions (2, 4) and (-3, 9), you would enter "(2,4),(-3,9)" (without the quotation marks).
●
Hi6942O
Jun 19, 2024
0
4
1
+713
Algebra
Simplify \dfrac{1}{\sqrt2+sqrt3}+\dfrac{1}{\sqrt2-sqrt3}.
Tottenham10
●
Hi6942O
Jun 19, 2024
0
3
2
+1981
Geometry
What are the coordinates of the points where the graphs of f(x)=x^3 + x^2 - 3x + 5 and g(x) = x^3 + 2x^2 intersect?
Give your answer as a list of points separated by commas, with the points ordered such that their -coordinates
read more ..
●
●
LiIIiam0216
Jun 19, 2024
«
latest
9341
9340
..
9298
9297
9296
9295
9294
..
2
1
»
Post New Question
4 Online Users
Top Users
+129733
CPhill
moderator
+118626
Melody
moderator
+36933
ElectricPavlov
+33617
Alan
moderator
+14966
asinus
moderator
+11912
rosala
+3146
admin
administrator
+2487
GingerAle
+1981
LiIIiam0216
+1859
tomtom
+1714
bader
Sticky Topics
Some guidelines for question askers.
What is Happening 5
Again a number puzzle. Multiply in writing.
Loads of fun printable number and logic puzzles
¤¤¤¤Welcome To Web2.0calc¤¤¤¤
How to display latex properly
Feature Questions 1 - Started 8th May 19
How to upload a picture.
If a question is ticked that does not mean you cannot continue it.
Should you consider anything before you answer a question?
Geometry Thread
PUZZLES
LaTex Coding
/calculator/bsh9ex1zxj
Historical post!
What is happening? Wrap #4
Great Questions to Learn From 2
Great Answers to Learn From
Reference Material
Information for new people.