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Show Digest for last: 2 Days | 3 Days | 5 Days | 1 Week | 2 Weeks Angle finding (in Geometry)
Point D is lies on side BC of triangle ABC such that CD=2BD. It turned out that angle ADC=60 and angle ABC=45. Find angle BAC.
 (No Solution Yet, 2 Comments) Submitted on 2023-12-09 by Danish Ahmed Khan Cubic root cyclic summation (in Just Math)
Let P(x) be a polynomial of degree 3 and x1,x2,x3 are the solutions of P(x)=0.

Let (P(1/3)-P(-1/3))/P(0)=8, (P(1/4)-P(-1/4))/P(0)=9 and x1+x2+x3=35.

Find the value of (x2+x3)/x1+(x1+x3)/x2+(x1+x2)/x3.
 (No Solution Yet, 2 Comments) Submitted on 2023-12-09 by Danish Ahmed Khan Bug on a Cube 4 (in Probability)
A bug is crawling North along a wire when it comes to a wire frame in the shape of a cube. The top and bottom faces of this cube are perfectly level with the bug arriving at one of the lower level corners labelled A. Corners B, C, and D are also on the lower level naming counterclockwise. Upper level corners labelled E, F, G, and H are directly above A, B, C, and D respectively. The only connections to the outside world are at A and C. The wire exiting the cube at C is headed North.

Thus the cube represents a type of temporary trap for the poor bug. The bug travels along the wires taking 1 second to go from one corner to another. When it gets to either A or C there is a chance it will exit, and continue walking North from C or South from A. Once the bug decides to go in the exit direction, it is instantly free (do not count any time for the exiting move)

Bug Logic:
1. The bug never travels back along the same wire (and cannot reverse direction on a wire).
2. When encountering multiple choices which are all level, each path has an equal chance of being chosen.
3. The bug prefers going up to going level; and prefers level to down. Each is a 2:1 preference.
4. At a corner, the bug first decides between up/level or level/down; then if the choice was "level", it applies Rule 2.

What is the probability the bug will exit North?
What is the expected value of the number of seconds spent on the cube?

Same two questions if there were no up/level and level/down preference, and all directions at a corner (except returning back the same way) were equally likely?

 (No Solution Yet, 0 Comments) Submitted on 2023-12-08 by Larry Triple angle perimeter minimized (in Geometry)
Let ABC be a triangle with integral side lengths such that angle A=3 * angle B. Find the minimum value of its perimeter.
 (No Solution Yet, 2 Comments) Submitted on 2023-12-08 by Danish Ahmed Khan Maximum of divisor contraints (in Just Math)
Positive integers a,b are such that 137 divides a+139b and 139 divides a+137b. Find the minimum possible value of a+b.
 (No Solution Yet, 2 Comments) Submitted on 2023-12-07 by Danish Ahmed Khan Alternating Differences (in Numbers)
Let X1, X2, X3, ..., Xn be a permutation of the integers 1,2,3,...,n.

Consider the sum:
abs(X1-X3) + abs(X2-X4) + abs(X3-X5) + ... + abs(Xn-2-Xn).

What is the mean value of this sum taken over all possible permutations?

 (No Solution Yet, 1 Comments) Submitted on 2023-12-07 by K Sengupta Square Rearranger (in Numbers)
Find the smallest three distinct whole numbers A, B and C such that you can rearrange the digits of A and B to get C^2, the digits of A and C to get B^2, and the digits of B and C to get A^2.

**** Leading zeroes are not allowed.

 (No Solution Yet, 1 Comments) Submitted on 2023-12-06 by K Sengupta Unlucky Horse (in Logic) Rating: 5.00
Seven horses in a farm in Kentucky,
Of three blacks, the oldest is a daddy;
Of two browns, the 3 year old male is called BILLY,

And the horse SNOWY is white as a lily.

Of two half-sister mares, the black won in the Derby
She's a shade lighter than her daughter, BEAUTY
BEAUTY and her cousin LUCKY, both half the age of their auntie,

But faster than either ROCKY or SUNNY.

Three of the horses are ready for the Derby,

A horse must be three years to be an entry;

Maybe this year the farm gets lucky, Their stallion's loss last year was a pity.

CHALLENGE: Describe the horse that lost in last year's derby.

 (Solution Posted, 0 Comments) Submitted on 2023-12-06 by K Sengupta Please log in:

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