When a mobile is sold at 6 percent profit, it gets Rs. 870 more than it is sold at 6 percent loss. So what is the purchase price of mobile?

If one number is 50 percent less than X and the other numbers are 20 percent less than X. What is the ratio of both the numbers?

A works twice as fast as B and B works twice as fast as C. All three working together can finish a task in 4 days with the help of D. If D alone can finish the same task in 16 days, then in how many days will A alone finish 75 % of the same task?

What is the value of $${\sqrt{1-cosA\over{1+cosA}}}$$?

The table given below shows the cost price and selling price of four articles.

What is the average value of loss of all articles?

A shopkeeper earns a profit of 15% after selling a book at 20% discount on the printed price. The ratio of the cost price and printed price of the book is : 

Direction : What value should come in place question mark(?) in the following questions?

4 × 5² – 3² × 7 + 6²=?+24

If one angle is half of its complementary angle, find that angle.