The age of a father is twice the square of the age of his son. Eight years hence, the age of the man will be 4 years more than 3 times the age of his son. Find their present ages.

Mr. Mehra sends his servant to the market to buy oranges worth ₹ 15. The servant having eaten three oranges on the way, Mr. Mehra pays 25 paise per orange more than the market price. Taking x to be the number of oranges which Mr. Mehra receives, form a quadratic equation in x. Hence, find the value of x.

An employer finds that if he increases the weekly wages of each worker by ₹ 5 and employs five workers less, he increases his weekly wage bill from ₹ 3150 to ₹ 3250. Taking the original weekly wage of each worker as ₹ x; obtain an equation in x and then solve it to find the weekly wages of each worker.

A trader bought a number of articles for ₹ 1200. Ten were damaged and he sold each of the remaining articles at ₹ 2 more than what he paid for it, thus getting a profit of ₹ 60 on the whole transaction.

Taking the number of articles he bought as x, form an equation in x and solve it.