If the least common multiple of two numbers, 1728 and K is 5184, then how many values of K are possible? 

What approximate value should come at place of the question mark(?) in the following question?

A number of friends decided to go on picnic and planned to spend Rs. 108 on eatables. Three of them however did not turn up. As a consequence, each one of the remaining had to contribute Rs 3. extra. The number of them who attended the picnic was:

In solving a problem, one student makes a mistake in the coefficient of the first degree term and obtains – 9 and – 1 for the roots. Another student makes a mistake in the constant term of the equation and obtains 8 and 2 for the roots. The correct equation was 

Four years ago, the respective ratio between the age of Ram and that of Sonu, was 4 : 9. Tina is ten years older than Ram. Tina is ten years younger than Sonu. What is Tina's present age? 

A shopkeeper has 11 books of same cost price. He sells the first book at certain price, then he sells second book at a price which is ₹ 1 less than the selling price of first book and then he sells third book at a price which is ₹1 less than the selling price of second book. Following this pattern, he sold all 11 books. If he sells sixth book at its cost price. Find the overall percent profit or loss on selling all 11 books.