For the following questions answer them individually
Average age of a team having 12 players is 23 years. If the age of the coach is also included, then the average age increases by 2 years. What is the age (in years) of the coach?
An item is sold at two successive gains of 30% and 20%. If the final selling price is Rs 31200, then what is the cost price (in Rs)?
The number of trees in a town is 17640. If the numbers of trees increases annually at the rate of 5%, then how many trees were there 2 years ago?
Aman and Kapil starts from Delhi and Gwalior respectively towards each other at same time. They meet at Mathura and then take 196 minutes and 225 minutes respectively to reach Gwalior and Delhi. If speed of Aman is 30 km/hr, then what is the speed (in km/hr) of Kapil?
The simple interest on a sum of money for 10 years is Rs 3130. If the principal becomes 5 times after 5 years, then what will be the total interest (in Rs) obtained after 10 years?
If $$\frac{11-13x}{x}+\frac{11-13y}{y}+\frac{11-13z}{z}=5$$, then what is value of $$\frac{1}{x}+\frac{1}{y}+\frac{1}{z}$$ ?
If $$\frac{(5x-y)}{(5x+y)}=\frac{3}{7}$$, then what is the value of $$\frac{4x^{2}+y^{2}-4xy}{9x^{2}+16y^{2}+24xy}$$ ?
In  the given figure. PQRS is a square and SRT is an equilateral triangle. What is the value (in degrees) of $$\angle$$ $$SOR$$ ?