A milkman buys some milk at 50Rs / ltr. He adds 1 / 5 water in milk and sells the mixture at 50Rs / ltr. Find out profit %? 

A person invested Rs 28000 at the rate of 8% per annum simple interest and Rs 26000 at the rate of 10% per annum compounded Interest compounded annually. What is the difference in the interest earned from two investments at the end of 3 years? 

The following pie-chart shows the monthly expenditure of family on various items. If the family spends Rs. 825 on clothing answer the question

What is the total monthly income of the family? 

The LCM of two consecutive even numbers is 144, find the numbers?

The ratio of the speeds of the two airplanes is 7:15. If the first airplane covers a distance of 1050 km in 3 hours, what is the speed of the second airplane?

If the average marks obtained by Balu, Benjamin and Babur is 80 and the average marks of Benjamin and Babur is 83, find marks obtained by Balu.

Selling price of an article is $${7\over6}$$ of cost price. What is the profit percentage?

Ratio of age of father, mother and son is 9:8:3. Five years hence sum of their age will be 95 years. Find the age of son 5 years ago.