Difference between revisions of "1978 IMO Problems/Problem 1"

(Problem)
 
Line 1: Line 1:
What Are Breather Valves? - Perfect Valve
+
==Problem==
 
+
Let <math> m</math> and <math> n</math> be positive integers such that <math> 1 \le m < n</math>. In their decimal representations, the last three digits of <math> 1978^m</math> are equal, respectively, to the last three digits of <math> 1978^n</math>. Find <math> m</math> and <math> n</math> such that <math> m + n</math> has its least value.
Breather valve have many applications, including vacuum alleviation or stress equalization on transmission, oil containers or reservoirs. Common uses can be located on solitary acting cylinders or valves to stop dust as well as foreign fragments from getting in ports available to the environment.
 
Breather valve is made to release warm, damp exhaled breath rapidly, helping to stop an unpleasant develop of heat inside the facepiece and increase convenience for respirator wearers. Greater than 20 sets Shot Molding Devices specifically for breathing valves and also exhalation shutoffs production. Self-owned molding moulds department as well as skilled moulds maker.
 
QC: manually, prior to packaging, the shutoffs will be evaluated one at a time by workers to get the malfunctioning items. Safe Packing: first transparent plastic bag, then container.
 
The Breather Valve Working Principe
 
Registered Use some carb cleaner to get the most of the sludge out of the cap. Obtain some Dawn into the rest cap, and also place it in the pot of water.
 
In addition to this, the group of our firm operates in closes coordination with each various other and satisfies a great deal of requirements in a specified time frame. Also, we highlight on performing various training sessions consistently for our experts in order to boost their skills and knowledge. For the advantage of our clients, we are using different repayment options to them like cash money, DD, and also online fund transfer.
 
 
 
 
 
 
 
 
Our layout is versatile for both below ground and also above ground storage tanks. For below ground storage tanks we provide breather Valve cum In-Line kind Flame Arrestors with which you can proceed the air vent line upwards as well as finish it with a U bend, this helps in preventing the vapour to be released right into the environment over human level, for over ground storage tanks we provide breather Valve orgasm End of Line Flame Arrestor.
 
Our pallets are made with utmost precission which ensures tight turned off and also lowers the chattering of the pallet considerably. The dead weight kind pallets can be replaced at a later phase if your procedure requirements have transformed. We additionally aid with the called for sizing and also selection of Breather Valves based on API 2000 - breather valve manufacturer.
 
This remedy makes it possible for the healing of vapors or pre-vents the launch of dangerous compounds right into the atmosphere. Wherever combustible liquids, gases or vapours are delivered as well as stored, fire arresters ought to be made use of. This will minimise the risk when the eruptive media are sparked as well as safeguard the factory, setup and also, most significantly, people. breahter valve.
 
We have effectively offered giants among the industry.
 
Types Of Breather Valves
 
The vent control shutoff (solenoid), or just vent shutoff manages the flow of outdoors air in as well as out of the charcoal container. In some automobiles, it's called Cylinder Close Shutoff (CCV).
 
Should gas storage tank hisses when opened up? The hiss is a typical sensation, ideally keep the containers at greater than 1/2 complete to maintain the fume formation and also vapor loss at check. Hiss indicates your fuel container vapor system is functioning correctly and also not releasing unsafe fumes out (breather valve manufacturer).
 
Pressure and vacuum cleaner security degrees are regulated with heavy pallets or springtimes and can be incorporated to provide the required Pressure/Vacuum settings. It prevails to combine pallet and spring systems in one system i. e. pressure setups require a spring area, whilst the vacuum setups utilize the pallet technique.
 
All about How Breather Valves Operate?.
 
This vacuum condition must be eased through a regulated opening on the container. Basically, the container needs to take in order to eliminate the opportunity of rupturing or imploding. As a result of its main feature, this Valve is called Breather Shutoff. Valve option need to be in conformity with American Oil Institute Criterion API 2000 or other relevant requirement.
 
 
 
 
 
 
 
 
We have effectively offered titans amongst the industry.
 
 
 
 
 
 
The vent control shutoff (solenoid), or just air vent shutoff manages the flow of outside air in as well as out of the charcoal canister. In some vehicles, it's called Canister Close Shutoff (CCV).
 
Should gas tank hisses when opened up? The hiss is a regular phenomenon, preferably keep the tanks at greater than 1/2 full to maintain the fume development as well as vapor loss at check. Hiss means your fuel container vapor system is working effectively and not releasing dangerous fumes out.
 
Pressure and vacuum cleaner security levels are managed with heavy pallets or springtimes and can be incorporated to provide the required Pressure/Vacuum setups. It is typical to incorporate pallet and also spring systems in one system i. e. stress setups require a springtime section, whilst the vacuum setups use the pallet technique.
 
Because of its primary feature, this Shutoff is called Rest Valve. Valve choice must be in accordance with American Petroleum Institute Requirement API 2000 or other appropriate requirement.
 
 
 
NTGD Breather Valve, Your <a href="https://www.breathervalve.net" rel="dofollow">breather valve manufacturer</ a> of Proven Quality & Trustworthy Service
 
  
 
==Solution==
 
==Solution==

Latest revision as of 00:21, 21 October 2021

Problem

Let $m$ and $n$ be positive integers such that $1 \le m < n$. In their decimal representations, the last three digits of $1978^m$ are equal, respectively, to the last three digits of $1978^n$. Find $m$ and $n$ such that $m + n$ has its least value.

Solution

We have $1978^m\equiv 1978^n\pmod {1000}$, or $978^m-978^n=1000k$ for some positive integer $k$ (if it is not positive just do $978^n-978^m=-1000k$). Hence $978^n\mid 1000k$. So dividing through by $978^n$ we get $978^{m-n}-1=\frac{1000k}{978^n}$. Observe that $2\nmid LHS$, so $2\nmid RHS$. So since $2|| 978^n$, clearly the minimum possible value of $n$ is $3$ (and then $489^n\mid k$). We will show later that if $n$ is minimal then $m$ is minimal. We have $978^{m-3}-1\equiv 0\pmod {125}\Leftrightarrow 103^{m-3}\equiv 1\pmod {125}$. Hence, $m-3\mid \varphi(125)\Rightarrow m-3\mid 100$. Checking by hand we find that only $m-3=100$ works (this also shows that minimality of $m$ depends on $n$, as claimed above). So $m=103$. Consequently, $m+n=106$ with $\boxed{(m,n)=(103,3)}$.

The above solution was posted and copyrighted by cobbler and Andreas. The original thread for this problem can be found here: [1] and [2]

Video Solution

https://www.youtube.com/watch?v=SRl4Wnd60os

See Also

1978 IMO (Problems) • Resources
Preceded by
First question
1 2 3 4 5 6 Followed by
Problem 2
All IMO Problems and Solutions