Registro
Ingresar
Información
Esta función requiere la aprobación de las cookies
Puede aprobar las cookies en la barra de notificaciones en la parte superior de esta ventana
Información
Esta función requiere la aprobación de las cookies
Inicio
Foro
^{+0}
Widgets
Formulario
Matemáticas
Ayuda
números complejos
cálculo diferencial
cálculo diferencial
Ecuaciones
Gráficas de funciones
Algebra lineal
Teoría de números
pourcentages
Fonctions estándar
Probabilidad
Trigonometría
Conversión de unidades
Unidades
Sobre
Impreso
Política de privacidad
Términos de Servicio
Credits
Google+
Facebook
Email de contacto
Sí, tengo 16 años o más
Política de cookies
Acepto las cookies de terceros utilizadas para mostrarme anuncios
personalizados
. También acepto que estas cookies se utilicen para compartir información sobre mi uso de este sitio con los proveedores de publicidad que pueden combinarla con otra información que les he proporcionado o que han recopilado de mi uso de sus servicios.
Acepto las cookies estrictamente necesarias que garantizan funciones sin las cuales no podría utilizar este sitio web como es debido.
Configurar
Acepto todas las cookies
cálculos
ilimitados
por hora
CPhill
Nombre de usuario
CPhill
Puntuación
106535
Stats
Preguntas
52
Respuestas
33292
52 Questions
33362 Answers
+9
549
14
+106535
HAPPY BIRTHDAY, HECTICTAR !!!
She is one of the best "answerers" on this site [ even though she IS from Alabama....well.....everyone can't be perfect !!!! (Hehehe!!) ]
lee mas ..
●
●
●
●
●
●
●
●
●
●
●
●
●
●
CPhill
14 oct. 2019
+41
1
1893
1
+106535
'Waiting For Moderation'
I see that this has been happening quite a bit.....
If you "right click" on the image and select "Copy Image Address".....you can open up a new browser window and paste this address into it.....hit "Enter"
lee mas ..
●
CPhill
21 oct. 2018
+56
1
2166
18
+106535
4th Anniversary For Me !!!
Been on this site for 4 years now.....my thanks to Melody (and Andrew) for recommending me as a "mod".....I've learned quite a bit and "met" a lot of good people on here.....I've even managed (somehow) to help some of them....!!!
lee mas ..
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
CPhill
13 mar. 2018
+22
1
1259
38
+106535
Hey, guys.....I'm going to be gone for awhile....If you can hang on....I'll answer as many questions as I know how in just a bit....
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
CPhill
6 mar. 2018
+25
1066
7
+106535
I'm Out Until This Afternoon...You Kids Have Fun !!!
●
●
●
●
●
●
●
CPhill
13 feb. 2018
+41
1
2294
8
+106535
HAPPY BIRTHDAY, HECTICTAR !!!!
You are a real asset to the forum.....!!!!!
Here's your cake.....enjoy.....!!!!
lee mas ..
●
●
●
●
●
●
●
●
CPhill
14 oct. 2017
+25
1
2008
2
+106535
Going To The Picnic
This one isn't too difficult....give it a try.....!!!!!
lee mas ..
●
●
CPhill
25 sept. 2017
+22
2
2974
7
+106535
How Much Do They Weigh ????
This is another problem from American puzzle-maker Sam Lloyd.....
Five little girls taken in couples weigh 129 pounds, 125 pounds, 124 pounds, 123 pounds, 122 pounds, 121 pounds, 120 pound, 118 pounds, 116
lee mas ..
●
●
●
●
●
●
●
CPhill
23 sept. 2017
+22
1
1387
5
+106535
The Width Of The River.....
Here is a problem I've always liked...it was devised by one of the great American "puzzleists" of all time, Sam Lloyd
It has been posted on the forum before, but not in a while.....maybe we have some new people who would like
lee mas ..
●
●
●
●
●
CPhill
20 sept. 2017
+28
1
1861
10
+106535
ReCaptcha Verification
I don't know if others are having this problem or not......when using Opera or Firefox I had to do the ReCaptcha thing when submitting answers.......however.......using Google Chrome seems to solve this problem - for me anyway....
Comments???
lee mas ..
●
●
●
●
●
●
●
●
●
●
CPhill
19 mar. 2017
+33
1
1953
6
+106535
Happy Pi Day..(3.14)....Everybody.....!!!!!
lee mas ..
hectictar
●
●
●
●
●
●
CPhill
14 mar. 2017
«
último
4
3
..
2
1
»
#1
+106535
+6
1. This is a "thinking" problem. For every fifth part of the tank that is filled, 1/12th of it is being drained away. In effect, the draining is retarding the filling.
So we have: (The portion of the tank being filled per hour) * (time it takes to fill) = (whole tank filled)
In math terms this equates to: (1/5 - 1/12) * X = 1
So we have: (7/60) * X = 1
I'll let you finish this one......just solve for X......your answer will be in hrs.
2. This is a trig problem. We have a triangle whose opposite side is 12 and whose hypotenuse is 24. To find the incline angle, take the sine inverse of 12/24.
3.If the wife gets 1/2 and the daughter gets 1/8, the son gets what's left = 3/8. Then, 3/8 of the estate is 30000.
Let X be the total amount of the estate.
In math terms, we have............. 3/8 * X = 30000
Again, I'll let you finish this one for yourself.
4. Since it rained 7 days out of 30, the probability it rained on any one day is just......... 7/30.
5. The letters don't matter. The first digit is a non-zero number and the other two digits can be any digit from 0-9 inclusive.
So, the possible numbers are from 100 - 999 inclusive. We have 900 of these......... (999-100+1)
So, the total numbers that are 400 or greater = (999-400+1) = 600
Therefore, the probability that a number is greater than 400 is just 600/900 = 2/3.
Hope that helps......good luck!!
CPhill
17 mar. 2014
#1
+106535
+6
If I read your question correctly, you'd like to convert a repeating mixed number like 1.5555..... to a fraction.
Here's the way to do this.
Suppose we have 1.5555.
Forget the whole number part - we can add that back later.
Write the rest without the decimal....i.e., 5555.
Put this over a denominator that has the same number of 9's as the number of digits in the decimal part....i.e., 9999.
So we have 5555 / 9999.
Check this with your calculator...I think you'll get .5555.
Add the 1 back to the front of the fraction. to get the mixed number = 1 + (5555/9999).
That's it.
CPhill
17 mar. 2014
#2
+106535
+6
Mmmmm....we have a dilemma here. If I take the cos inverse of (-32/40), I get about 143 degrees. But, if I take the sin inverse of ( 35/40), I get about 61 degrees.- or an angle of about 119 degrees, since the angle is in the second quadrant.
The other problem is that the hypotenuse = 40. But, SQRT((-32)^2 + (35)^2) = about 47.72. So, one hypotenuse is greater than the other.
Check your problem, ara, and see if your numbers are correct. (The sin and cos inverses of your original problem produce different angles, too)
As Melody said before, someone else is free to check any flaws in my logic!!
CPhill
17 mar. 2014
#1
+106535
+6
I'll get you started, and you can finish.
At the end of the first year, Korey can expect to make 12000*(1.06).
At the end of year 2, that rises to 12000*(1.06)*(1.06) = 12000(*(1.06)^2
So, at the end of N years, Korey can expect profits of 12000*(1.06)^N
CPhill
17 mar. 2014
#2
+106535
+6
Mmmmm....let's look at this again.....
I believe you're saying that she can read 2/9 of her book everyday and she has 2/3 left to read.
Let x be the number of days that it will take her to finish the book.
Then..... (the part of the book she can read each day) * (days it will take her) = (the rest of the book)
Does this give you a hint about how to solve the problem??
CPhill
16 mar. 2014
#1
+106535
+6
Are you trying to find the slope between these two points?? Write the equation of a line??
CPhill
16 mar. 2014
#1
+106535
+6
(1.04)^9 = 1.4233........ i.e., about 42.33%
CPhill
16 mar. 2014
#1
+106535
+5
This isn't a "technical" proof, but let me give you an example that may help you to see why it's true.
Suppose we have (2^2)^3
What is this??
It's just (2*2) * (2*2) * (2*2). In other words, we're just "cubing" (2*2).
But, this is just 2 * 2 * 2 * 2 * 2 * 2 = 2^6 = 2^(2*3)
So, (2*2)^3 = 2^(2*3)
Does that help??
CPhill
16 mar. 2014
#1
+106535
+5
Volume of a sphere = (4/3)*Pi*R^3
Thus:
(42.1)*(3/4)/(Pi) = R^3
Simplify the left side, and take its cube root. This will give you the radius. Double that to get the diameter in meters.
CPhill
15 mar. 2014
#1
+106535
+10
Use this formula to calculate the amount at the end of five years:
A = P(1 + R/T)^(NT).........
Where
P = principal amount (the initial amount you borrow or deposit)
R = annual rate of interest (as a decimal)
T = number of years the amount is deposited or borrowed for.
A = amount of money accumulated after N years, including interest.
N = number of times the interest is compounded per year
So, using your info, we have,
A = 2000(1 + .02/4)^(4*5)
A = 2000*(1.005)^(20)
Remember to do the exponent first, and you should be able to take it from there!!
Hope this helps
CPhill
15 mar. 2014
«
último
3335
3334
..
2
1
»