What is the value of the expression?

(tan0° tan1° tan2° tan3° tan4° …… tan89°)

The water in a river is flowing at the rate of 4 km/hr. If the width and depth of the river is 8m and 4m respectively, then how much water will enter the sea in 15 minutes.

The income of Aman is Rs. 30,000 per month and his expenditure is Rs. 20,000 per month. In the next month, his income increases by Rs. 10,000 per month, and expenditure increases to Rs. 25,000 per month. In the next month, his savings increases by what percent?

A metallic solid spherical ball of radius 3 cm is melted and recast into three spherical balls. The radii of two of these balls are 2 cm and 1.5 cm. What is the surface area (in cm²) of the third ball?

The area of a right-angled isosceles triangle having hypotenuse 16√2 cm is

The salary of a person is increased by 20%. By what % the new salary must be reduced to restore the original salary?

If $${45\over53}={1\over{a+{1\over b+{1\over c-{2\over 5}}}}}$$  , where a, b and c are positive integers, then what is the value of (4a-b+3c)?

 if $$tan(A+B)=\sqrt { 3} \ $$ and $$ tan(A-B)= {1\over \sqrt { 3} \   }; 0^0<(A+B)<90^0;A>B, $$ then the value of A and B are