A tap drips at a rate of one drop/sec. 600 drops make 100ml. The number of litres wasted in 300 days is: 

A sum is to be paid back in 3 equal annual instalments. The interest is compound annually at 30% per annum. If each instalment be Rs.21970 then what is the sum?

Inside a square ABCD, triangle BEC is an equilateral triangle. If CE and BD intersect at O, then ∠BOC is equal to?

Directions : What should come in place of the question mark (?) in the following number series? 

55 109 ? 433 865 1729 

An article is sold at a loss of 20 %. It yields Rs. 60 more when it is sold at a gain of 20 %. The cost price of the article is 

Two mobile phones were purchased at the same price. One was sold at a profit of 30 % and the second was sold at a price which was Rs 2500 less than the price at which the first was sold. If the overall profit earned by selling both the mobile phones was 5 %, what was the cost price of one mobile phone? 

Simplify the following equations.
1 ÷[{p²/(p+6)}+{6p/(p+6)}]