11. 
A is 3 years older to B and 3 years younger to C, while B and D are twins. How many years older is C to D? 


12. 
The 30 members of a club decided to play a badminton singles tournament. Every time a member loses a game he is out of the tournament. There are no ties. What is the minimum number of matches that must be played to determine the winner ? 


13. 
In a garden, there are 10 rows and 12 columns of mango trees. The distance between the two trees is 2 metres and a distance of one metre is left from all sides of the boundary of the garden. The length of the garden is 


14. 
12 year old Manick is three times as old as his brother Rahul. How old will Manick be when he is twice as old as Rahul ? 


15. 
A tailor had a number of shirt pieces to cut from a roll of fabric. He cut each roll of equal length into 10 pieces. He cut at the rate of 45 cuts a minute. How many rolls would be cut in 24 minutes ? 

