Question

Please solve my doubt:

1)A number is increased by 25% and then reduced by 25%.Find the net increase or decrease percent.

2) A number is increased by 10% and then decreased by 10%.Find the net increase or decrease percent.

Note : My doubt is that please kindly,I request you that solve both the questions with a exactly same process/formula.
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Answer 1

Answer:

Starting with x

Increase by 25% results in 1.25x

Decrease by 25% results in 0.75*1.25x=0.9375x

Net change from x to 0.9375x is -0.0625x

which indicates a decrease by 6.25%

Answer 2

Answer:

1st answer

Let the original price of the book be Rs. 100. 

Decreased price of the book = Rs. 75 

Increased price of the book after 20% increase

=120/100 × Rs. 75= Rs. 90

∴ Net change in price = Rs. 10 decrease 

∴ % change =10/100 ×100=10% decrease