Percentage

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• If the price of a commodity increases by r %, then reduction in consumption, so as not to increase the expenditure is .
• If the price of a commodity decreases by r%, then the increase in consumption so as not to decrease the expenditure is
• First Increase and then decrease :
• If the value is first increased by x % and then decreased by y % then there is  increase or decrease, according to the +ve or â€“ve sign respectively.
• Student and Marks
• The percentage of passing marks in an examination is x%. If a candidate who scores y marks fails by z marks, then the maximum marks M =
• A candidate scoring x % in an examination fails by â€˜aâ€™ marks, while another candidate who scores y% marks gets â€˜bâ€™ marks more than the minimum required passing marks. Then the maximum marks .
• If Aâ€™s income is r % more than that of B, then Bâ€™s income is less than that of A by
• If Aâ€™s income is r % less than that of B, then Bâ€™s income is more than that of A by