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Easy expected value problem
Kempu33334   6
N 3 hours ago by aidan0626
Source: Me

Bob takes two real numbers, $x$ and $y$, independently at random from the range $0$ to $1000$. He then selects an operation out of $+$, $-$, and $\times$ and performs that operation on them. Find the expected value of the answer.
6 replies
Kempu33334
Today at 2:17 PM
aidan0626
3 hours ago
Challenge Problem in Similar Triangles
yes45   0
Today at 5:26 PM
\(\triangle ABC\) has a right angle at \(B\). \(AB = 9\) and \(AC = 15\). Point \(D\) lies on \(AB\) such that \(AD = 2\) and point \(E\) lies on \(AC\) such that \(AE\) = \(\frac{12}{5}\). Find the perimeter of \(BCED\).
Answer Confirmation
Solution
0 replies
yes45
Today at 5:26 PM
0 replies
Interesting Geometry
captainmath99   0
Today at 5:11 PM
Let ABC be a right triangle such that $\angle{C}=90^\circ, CA=6, CB=4$. A circle O with center C has a radius of 2. Let P be a point on the circle O.

a)What is the minimum value of $(AP+\dfrac{1}{2}BP)$?

b) What is the minimum value of $(\dfrac{1}{3}AP+BP)$?
0 replies
captainmath99
Today at 5:11 PM
0 replies
[PMO27 Qualis] III. 1 Binary Counting
tapilyoca   5
N Today at 4:44 PM by Magdalo
John wrote down all of the numbers from 1 to 128 in binary. How many 1's did he write?
5 replies
tapilyoca
Nov 23, 2024
Magdalo
Today at 4:44 PM
22nd PMO Qualifying Stage #11
pensive   3
N Today at 4:31 PM by Magdalo
Let $x$ and $y$ be positive real numbers such that
\[
\log_x 64 + \log_{y^2} 16 = \frac{5}{3} \quad \text{and} \quad \log_y 64 + \log_{x^2} 16 = 1
\]What is the value of $\log_2 (xy)$?

Answer
3 replies
pensive
Today at 2:48 PM
Magdalo
Today at 4:31 PM
[PMO22 Qualifying] I.11
Magdalo   3
N Today at 4:30 PM by Magdalo
Let $x$ and $y$ be positive real numbers such that
\[\log_x64+\log_{y^2}16=\dfrac{5}{3}\text{  and  }\log_y64+\log_{x^2}16=1 \]Find $\log_2(xy)$
3 replies
Magdalo
Today at 3:49 PM
Magdalo
Today at 4:30 PM
Log Rationality
Magdalo   1
N Today at 4:30 PM by Magdalo
Let $x+y=36$ be positive integers. How many pairs of $x,y$ are there such that $\log_xy$ is rational?
1 reply
Magdalo
Today at 4:28 PM
Magdalo
Today at 4:30 PM
Original Problem U1
NeoAzure   1
N Today at 4:24 PM by NeoAzure
How many three-digit positive integers are divisible by 4 and have exactly two even digits?

Solution

Answer
1 reply
NeoAzure
Today at 4:24 PM
NeoAzure
Today at 4:24 PM
[Sipnayan 2017 JHS] Semifinals A, Difficult, P2
NeoAzure   1
N Today at 4:06 PM by NeoAzure
Akira fills an urn with 10 chips such that 1 chip is labeled “1”, 2 chips are labeled “2”, 3
chips are labeled “3”, and 4 chips are labeled “4”. She draws 4 chips from the box without
replacement. What is the probability the sum of the numbers labeled on the 4 chips is divisible
by 3

Solution

Answer
1 reply
NeoAzure
Today at 4:06 PM
NeoAzure
Today at 4:06 PM
Inequalities
toanrathay   2
N Today at 4:00 PM by MathsII-enjoy
Let $a,b,c$ be positive reals such that $1/a+1/b+1/c-9/4abc=3/4$, find $\min$ of $P=a^2+b^2+c^2$.
2 replies
toanrathay
Today at 6:35 AM
MathsII-enjoy
Today at 4:00 PM
a