1) The price of sugar increases by 25%. By what % must a house-wife reduce her consumption so that the expenditure does not increase.
2) In an examination, 95% of candidates passed and 25 failed. How many candidates appeared for the examination?
Here is the similar link for your second query.
I am Arpit Saini of 7th Standard And I wants to tell you the answer of 1st question
Rate of sugar = Rs 100 per kg (say)
Consumption in month = 100kg (say)
Expenditure on sugar = 100 *100
Increase in price of sugar (25%) = 25/100*100
= Rs 25
New price of sugar =100+25
Expenditure on petrol =Rs 10000
So,New consumption of sugar = 10000/125
Reduction in consumption of sugar in percentage = 100-80