The difference between the selling prices of a keyboard at losses 15% and 25% is Rs. 50. Then the cost price of a keyboard is :

If a chord of length 30 cm is at a distance of 8 cm from the center of the circle, then the length of the chord of the same circle which is at a distance of 15 cm from the center is equal to

A takes twice as much time as B and thrice as much as c to complete a piece of work. They together complete the work in 1 day. in what time, will A alone complete the work. 

Directions : The graph shows the demand and production of different companies. Study the graph and answer the following questions.

The demand of company B is what percentage of the production of company F ?

A train passes a 100 meters long platform in 28 seconds and a man standing on the platform in 20 seconds. The speed of the train is:

Comprehension: Read the following chart and answer the following questions.

What is the average death rate per day for the week? 

Six years ago, the ratio of the ages of Kunal and Sagar was 6 : 5. Four years hence, the ratio of their ages will be 11 : 10. What is Sagar's age at present?

Find the value of $$ {\sqrt{(cos^{2}20°+cos^{2}70°)}}$$