Quantitative Aptitude - Arithmetic Ability Questions

Dev lent Rs. 8000 to Jairam for 17 years and Rs. 4700 to Karnik for 16 years on simple interest at the same rate of interest and received Rs. 21120 in all from both of them as interest. The rate of interest per annum is:

A wholesaler sells a jacket to a retailer at a profit of 5% and the retailer sells it to a customer at a profit of 10%. If the customer pays Rs. 4158, what had it cost (in Rs) to the wholesaler?

If x2+ x = 19, then what is the value of (x + 5)2+ [1/(x + 5)2]?

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

At 20% discount the selling price of an article is Rs 2400, what is the selling price (in Rs) if the discount is 32.5%?

Pranita got 30 marks more in Math than what she got in Science. Her Math marks are 60% of the sum of her Math and Science marks. What are her Science marks?

A car travels 80 km in 2 hours and a train travels 180 km in 3 hours . The ratio ofspeed of the car to the train is

A man bought 25 crates of oranges for Rs. 10,000. He lost 5 crates. In order to earn a total profit of 25% of the total cost, he would have to sell each of the remaining crates at