A number is increased by 40% then again by 40%. Then it is decreased by 40%. By what percent the original number has changed?
Correct Answer: Option C
Let original number be 100x.
According to question, the number is first increased by 40%
∴ New number = 100x + (40% of 100x) = 100x + 40x = 140x
It is again increased by 40%.
∴ New number = 140x + (40% of 140x) = 140x + 56x = 196x
Now, this number is decreased by 40%.
∴ New number = 196x – (40% of 196x) = 117.6x
∴ Percentage change in original number \(= \;\frac{{117.6x\; - \;100x}}{{100x}} \times 100\; = \;17.6\)
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