Quantitative Aptitude - Arithmetic Ability Questions

In each of the following questions two equations I and II are given. Solve both the equations and give answer:
$$\begin{gathered} I. x2+2x-195=0 \\ II. y2+30y+225=0 \end{gathered}$$

Mahanath works 2 times as fast as Sahay. If Sahay can complete a job alone in 21 days, then in how many days can they together finish the job?

On a certain principal if the Simple interest for two years is Rs 3000 and Compound interest for the two years is Rs 3225, what is the rate of Interest?

If the radius of a circumscribed circle in an equilateral triangle is 14 cm. Then what will be the radius (in cm) of the inscribed circle?

After two successive discounts of 20% and 35%, an article is sold for Rs 50700. What is the marked price (in Rs) of the article?

A bookseller bought 500 text books for  20,000. He wanted to sell them at a profit so that he get 50 books free. At what profit percent should he sell them?

Mr. Rajesh buys a toy for Rs. 27.50 and sells it for Rs. 28.60. Find the gain %.

What is the simplified value of Sec ACot A + Tan A2 ?