Some students (only boys and girls) from different schools1 appeared for an Olympiad exam. 20% of the boys and 15% of the girls failed the exam. The number of boys who passed the exam was 70 more than that of the girls who passed the exam'. A total of 90 students failed. Find the number of students that appeared for the exam.

In a group of 20 singers and 40 dancers, 20% of the singers are less than 25 years old and 40% of the entire group are under 25 years. What percentage of dancers are under 25 years?

Ajay spends 25% of his salary on house rent, 5% on food grains, 15% on travel and 10% on clothes and saves 27000, what is Ajay's monthly income?

A man's annual income has increased by Rs. 5 lakhs but the tax on income that he has to pay has reduced from 12 % to 10 %. He now pays Rs. 10,000 more income tax. What is his increased income (in Rs. lakhs)? 

Average salary of Santosh and Renu is Rs 3600. If salary of Santosh and Renu is increased by 50% and 30% respectively then their total salary is increased by 35% then find salary of Renu is what percent more or less than salary of Santosh before increment?

In an office, 70% of the total number of employees are females. 80 % of the total number of employees, including 85 males, got promotion. If there are 105 female employees, then what percentage of female employees got promotion?

B got 20% marks less than A. What per cent marks did A got more than B? 

A number, on subtracting 15 from it reduces to its 80 %. What is 40 % of the number?