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

If $$ {66{2\over 3}}{ \%}$$ of 75 % of one-eighth of a certain number is 179, then $$ {33{1\over 3}}{ \%}$$ of three – fourth of that number is:

What percentage of the whole week does Ajay spend in office, if his office hours are 9 am to 5 pm from Monday to Friday? 

60% boys are failed in History and 65% boys are failed in Geography while total 30% boys are failed in both the subjects. If total 1200 boys appeared in the examination then total how many boys are passed?

A student got 30% marks in an examination and failed because he got 12 marks less. Another student got 40% marks in the same examination and got 18 marks more than the minimum passing marks. Must have marks to pass

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?

A man spends a part of his monthly income and saves the rest. The ratio of his expenditure to the saving is 61 : 6. If his monthly income is Rs .8710, the amount of his monthly saving is 

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