Mathematics Stack Exchange
Mathematics Stack Exchange

Questions tagged [problem-solving]

Use this tag when you want to determine the thinking that is needed to solve a certain type of problem, as opposed to looking for a specific answer to a question.

Use this tag when you want to determine the thinking that is needed to solve a certain type of problem, as opposed to looking for a specific answer to a question.

4495 questions
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What are the $5$ different combinations of $4$ numbers that can add to $8, 9, 10$ or $11$?

There are $5$ combinations of $4$ numbers from $1-9$. If you write these on two coins, so there are $2$ numbers on each coin. Then you flip the coin. The sum of the two numbers add to $8,9,10,$ or $11.$ In other words, you can combine $2$ numbers to…
SuperNinja741 Does Gaming
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Three screw problem

There are three identical screws with diffrent amounts of nuts and disks on them. Here is the problem picture: How do you calculate the weight of a screw, the nuts and the disks?
William Johansson
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Solving two variables with one equation

I have been trying to solve the following equation, but I am still stuck after trying many different methods. I have been given this equation to solve: $$(1 + z^{-1})^4 (a + bz^{-1} + az^{-2}) - (1 - z^{-1})^4 (a - bz^{-1} + az^{-2}) = 2z^{-d}$$ I…
James the Great
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Solution of $x+\log(x)=c$

how to solve the following equation? $x+\log(x)=n+c$,where $c$ is constant, and $n$ is positive number and allow to be infinity. Intuitively, if let $n \to \infty$， the approximate solution will be $x=n+c-\log(n)$, can any one help with the exact…
cindy
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Basic Math Question for Health Care

This is super basic, but I have not been in school for YEARS. I am a bit dusty. Any-who, Its a common word problem, and as follows: A licensed practical nurse gives 1800 milligrams of penicillin over a 36 hour time period. If the dosage occurs…
Robert
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How to solve for X in this equation?

$$n * x * cos(\frac{\pi}2 * \frac{x}{x+b}) + c = y$$ How would I get X on one side of the equation instead of y? Normally I work the equation forwards knowing X. The other variables are constants. for example: $$0.000025 * 1000 * cos(\frac{\pi}2 *…
J. Doe
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Math problem puzzle

My grandson is about as many days as my son in weeks, and my grandson is as many months as I am in years. My grandson, my son and I together are 120 years. Can you tell me my age in years ? It's really simple : The above system of 3 equations in 3…
Manal
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Mathematic problem solution

I need help with this question: When a positive integer $n$ is written in the blackboard, an allowed operation is to substitute it with a number $ab$, where $n=a+b$, and both $a$ and $b$ are positive integers. If $n$ is initially $24$, does there…
Mathuser
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Mowing the lawn problem solving question

Andrew can mow the lawn in 30 minutes and Nicholas can mow the same section of lawn in 45 minutes. Working together, in how many minutes could they mow the lawn? I know the answer is 18 minutes but I don't know how the answer was solved. HELP ASAP,…
MAL
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intuition behind LCM method used to solve time/work aptitude problems

Below is a sample time/work problem. Rakesh alone can do a work in 10 days. Brijesh can do the same job in 15 days. If both Rakesh and Brijesh work together, then in how many days the work will get completed? Above problem can be solved using LCM…
Akash
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For any positive integer $n$ there exists an $n$-digit number divisible by $2^n$ and containing only the digits $2$ and $3$

Prove that for any positive integer $n$ there exists an $n$-digit number divisible by $2^n$ and containing only the digits $2$ and $3$ Need help solving by induction
Anonymous
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3 hours ago the distance to 10 a.m is as twice as the distance to 1 hour. What time is it now?

The question in the title. I think the answer is 11:00 a.m but I am not sure.
jsm joyce
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How many eggs are there in the basket?

There is a basket of eggs. The remainder is $1$ when we put the eggs in groups of $2$. $2$ when we put the eggs in groups of $3$. $3$ when we put the eggs in groups of $4$. $4$ and $5$, respectively, when we put the eggs in groups of $5$ and…
Peaceyou
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Solution at $(z+1)f(x) - zf(-x) = x^4$

I need your help on $(z+1)f(x) - zf(-x) = x^4$ a) Prove f is even. b) Find $f(x).$ Can you help me?
Dgg 7000
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Problem solving - Which will run out first?

I have a problem solving question I've been having difficulty wrapping my head around. Let's say there are 5 different coal power stations each uses up coal at a different rate each has a different amount of coal reserve each gets more coal shipped…
Thomas Shemeld
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