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#1 2018-08-05 15:27:48

Zeeshan 01
Member
Registered: 2016-07-22
Posts: 746

Increase and decrease in quantity

If 450 is first increased by 10% and then decreased by 15%  , Then the resulting number is?


Malik

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#2 2018-08-05 17:13:31

Jai Ganesh
Administrator
Registered: 2005-06-28
Posts: 45,956

Re: Increase and decrease in quantity

Hi Zeeshan 01,

450 is increased by 10% : Resulting in 450 + 45 = 495.
Later, it is decreased by 15%.
That is, 495 - (15/100) x 495 = 495 - 74.25 = 420.75.

If the problem is intended : 450 is first increased by 10% and decreased by 15%, the net effect being decrease in 5%;
In this case, the value would be 450 - 450 x 5/100 = 450 - 22.5 = 427.50.


It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

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#3 2018-08-05 20:24:19

Zeeshan 01
Member
Registered: 2016-07-22
Posts: 746

Re: Increase and decrease in quantity

Ok! The difference between these two


Malik

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#4 2018-08-05 23:52:30

Jai Ganesh
Administrator
Registered: 2005-06-28
Posts: 45,956

Re: Increase and decrease in quantity

Hi,

The difference between the two : 427.50 - 420.75 = 6.75.

This can be calculated with any hand held calculator.


It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

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#5 2018-08-06 03:20:32

Zeeshan 01
Member
Registered: 2016-07-22
Posts: 746

Re: Increase and decrease in quantity

Not this difference , Means the difference between methods and when to use


Malik

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#6 2018-08-06 13:49:41

Jai Ganesh
Administrator
Registered: 2005-06-28
Posts: 45,956

Re: Increase and decrease in quantity

Hi,

The first method is technically correct.

It is always advisable to use this method.

The second method may give more of less the same value.

This is for the beginners.


It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

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