question:If anitha rows 65 km upstream and 105 km down steam taking 13 hours each, then the speed of the stream
Options:
(A) 8.4 kmph
(B) 5.5 kmph
(C) 6 kmph
(D) 8 kmph
(E) 8.2 kmph
answer:(D)
Stream of consciousness:Speed upstream = 65/13 = 5 kmph
Speed down stream = 105/5 = 21 kmph
Speed of stream = (21-5) = 8 kmph

question:A family with 1 mother, 1 father, and 2 children sit in a car with 2 front seats and 2 back seats. If the mother drives with a child in the front, and the father sits in the back center seat with the other one children on either side of him, how many seating arrangements are possible?
Options:
(A) 3
(B) 4
(C) 6
(D) 8
(E) 10
answer:(C)
Stream of consciousness:Mother has a fixed place and father, so there are 3*2 ways to arrange the children, hence

question:The average of seven numbers is 4. The average of first three numbers is 2 and the average of last three numbers is 6. What is the middle number?
Options:
(A) 3
(B) 4
(C) 6
(D) 7
(E) 8
answer:
(B)
Stream of consciousness:The total of seven numbers = 7X4 = 28
The total of first 3 and last 3 numbers is = 3 X 2+3 X 6 = 24
So, the middle number is (28 - 24 ) = 4