TCS Selection process and patterns

Selection process:
1) written test
2) Technical cum HR interview.
Written Test: Written test consists of 35 questions 80min, previously it is 60min but now time they increased 20min. It is a online test .
 Preparation: Up to my knowledge questions for written test is always from previous papers.so first of all solve below patterns mostly all these patterns are repeated in written test.and try previous papers given by various users in freshersworld and prepare quantitative aptitude by R.S Agarwal
 Pattern 1:
1. (1/2) of a number is 3 more than the (1/6) of the same number?
 a) 6 b)7 c)8 d)9
Solution:    Let the number be x,
                  ((1/2)*x)=3+(1/6)*x,
                   Then solve x
2. (1/3) of a number is 3 more than the (1/6) of the same number?
a) 6 b)16 c)18 d)21
 3. (1/3) of a number is 6 more than the (1/6) of the same number?
 a) 6 b)18 c)36 d)24
 4. (2/3) of a number is 4 more than the (1/6) of the same number?
a) 6 b)8 c)36 d)24
5. (1/3) of a number is 5 more than the (1/6) of the same number?
 a) 6 b)36 c)30 d)72
Pattern 2: 
1. There are two water tanks A and B, A is much smaller than B. While water fills at the rate of 1 liter every hour in A, it gets filled up like, 10, 20, 40,80, 160…..in tank B. (At the end of first hour, B has 10 liters, second hour it has 20 liters and so on). If tank B is 1/32 filled of the 21 hours, what is total duration of hours required to fill it completely?
a) 26 B)25 c)5 d)27
 Solution: for every hour water in tank in B is doubled,
Let the duration to fill the tank B is x hours.
x/32 part of water in tank of B is filled in 21 hours,
Next hour it is doubled so, 2*(x/32) part i.e (x/16) part is filled in 22 hours,
 Similarly (x/8)th part in 23 hours,
(x/4)th part is filled in 24 hours,
 (x/2)th part is filled in 25 hours,
(x)th part is filled in 26 hours So answer is 26 hours.

2. There are two pipes A and B. If A filled 10 liters in an hour, B can fill 20 liters in same time. Likewise B can fill 10, 20, 40, 80, 160…... If B filled in 1/16 of a tank in 3 hours, how much time will it take to fill the tank completely?
 a) 9 B)8 c)7 d)6