In a competitive exam, the minimum qualifying percentages for Category A and Category B jobs are 25% and 45%, respectively. A candidate scored 83 marks and failed to get a Category B job by 25 marks. What is the minimum qualifying marks to secure a Category A job?

A person who spends $$ 16{2\over3}\% $$ of  his income is able to save 1200 per month. His monthly expenses (in) is:  

In an examination, 92% of the students passed and 480 students failed. If so, how many students appeared in the examination?

A man spends 75 % of his income. His income increased by 20 % and he increased his expenditure by 15 %. His savings will then be increased by: 

A student has to score 33% marks to pass. He gets 117 marks and fails by 81 marks. Find the student’s marks percentage?

A dozen pairs of socks quoted at 180 are available at a discount of 20 %. How many pairs of socks can be bought for 48? 

If X is 20% less than Y, then find the value of $${Y-X\over Y}$$ and $${X\over X-Y }$$

The average marks obtained in a class of 50 students is 70%. The average of first 25 is 60% and that of 24 is 80%. What is the marks obtained by the last student?