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

1) suppose a number 100

let us increase it by 25%

so 25% of 100

= 25/100 × 100

= 25

so the new number formed = 100 + 25

=125

now 125 is decreased by 25%

so 25% of 125

= 25/100 × 125

= 31.25

so the new number formed = 125 - 31.25

= 93.75

so the net decrease is = 100-93.75

= 6.25

so net decrease percentage = 6.25/100 × 100

= 6.25%

2) Suppose a number 100 is increased by 10%

so, 10% of 100

= 10/100 × 100

= 10

so the new number formed = 100+10

= 110

now 110 decreased by it's 10%

so, 10% of 110

= 10/100 × 110

= 11

so the new number formed = 110-11

= 99

now the net decrease = 100-99

= 1

net decrease percentage = 1/100 × 100

= 1%

hope you understand the answer