The reduction of Rs . 12 in the selling price of an article will changes 5 % gain into  $$ 2{1\over 2}\% $$ loss . The cost price of the article is 

When a diagonal of a square is 24 cm then find out of its perimeter.

The ratio between the boys and girls in a class is 6:5 respectively. If 8 more boys join the class and two girls leave the class then the respective ratio become 11:7. What is the number of boys in the class now?

A train is traveling at the rate of 45km/ hr. How many seconds will take to cover a distance of $$ {4\over5} $$ km? 

The circle-graph given here shows the spending of a country on various sports during a particular year. Study the graph carefully and answer the question given below it.

If the total amount spent on sports during the year was Rs. 2 crores, the amount spent on cricket and Hockey together was:

A 160-meter-long train running at a speed of 90 km/h crosses a platform is 18 s. What is the length of the platform in metre?

A trader had 2000 kgs of rice. He sold a part of it at 10 % profit and the rest at 16 % profit so that he made a total profit of 14.2%. How much rice (in kg) did he sell at 10 % profit? 

The average age of 30 students is 9 years. If the age of their teacher is included, the average age become 10 years. The age of the teacher ( in years ) is