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Question
For an amount, explain why, a 20% increase followed by a 20% decrease is less than the original amount.
Solution
Let us assume the amount be Rs. 100
⇒ x% increase in amount = Amount + `x/100` × Amount
⇒ 20% increase in Rs. 100 = `100 + 20/100 xx 100`
= 100 + 20
= Rs. 120
⇒ x% decrease in amount = Amount – `x/100` × Amount
Now, 20% decrease in Rs. 120 = `120 - 20/100 xx 120`
= 120 – 24
= Rs. 96
Hence, decreased price is less than original amount.
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