Primary level maths problem, please help
Primary level maths problem, please help
Hey guys,
I am no maths genius and need help with this itsy bitsy problem. I know I can easily find the solution by adding them one by one but I was wondering if someone can come up with a quicker solution to this problem, some sort of a formula I guess.
This is the problem:
A train will hold 78 passengers. If it starts out empty and picks up one passenger at the first stop, two passengers at the second stop, 3 passengers at the third stop and so on. After how many stops will it be full?
Thanks, appreciate the help
I am no maths genius and need help with this itsy bitsy problem. I know I can easily find the solution by adding them one by one but I was wondering if someone can come up with a quicker solution to this problem, some sort of a formula I guess.
This is the problem:
A train will hold 78 passengers. If it starts out empty and picks up one passenger at the first stop, two passengers at the second stop, 3 passengers at the third stop and so on. After how many stops will it be full?
Thanks, appreciate the help

 Posts: 57
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Re: Primary level maths problem, please help
Well,this simply reduces the problem to the sum of n consecutive positive integers,which follows the equation :n(n+1)=156,simply factoring the expression,we find n=12 and n cannot be 13 as it is a negative integer.This just solves our problem that at the 12th stop,the bus would be full...
 M. M. Fahad Joy
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Re: Primary level maths problem, please help
How have you solve the problem? Can someone suggest me?
Math is the main inspiration of my life.
 samiul_samin
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Re: Primary level maths problem, please help
SolutionM. M. Fahad Joy wrote: ↑Sat Feb 17, 2018 9:39 pmHow have you solve the problem? Can someone suggest me?
 M. M. Fahad Joy
 Posts: 120
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Re: Primary level maths problem, please help
samiul_samin wrote: ↑Sat Feb 17, 2018 10:43 pmSolutionM. M. Fahad Joy wrote: ↑Sat Feb 17, 2018 9:39 pmHow have you solve the problem? Can someone suggest me?
No, I said by the rules on N(N+1)
Math is the main inspiration of my life.
 samiul_samin
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Re: Primary level maths problem, please help
Here is the Rule
 M. M. Fahad Joy
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Re: Primary level maths problem, please help
Thanks, understood. But how do you solve the equation?
n(n+1) = 156
Math is the main inspiration of my life.
 samiul_samin
 Posts: 1004
 Joined: Sat Dec 09, 2017 1:32 pm
Re: Primary level maths problem, please help
Hint
Answer
 M. M. Fahad Joy
 Posts: 120
 Joined: Sun Jan 28, 2018 11:43 pm
 Location: Bhulta, Rupganj, Narayanganj
 Contact:
Re: Primary level maths problem, please help
How can I get the rate of 'n'
Math is the main inspiration of my life.
 samiul_samin
 Posts: 1004
 Joined: Sat Dec 09, 2017 1:32 pm
Re: Primary level maths problem, please help
$n=12,13,n>0$ so,$n=12$