Q6. 
The digits of a three number are in $AP$. If the number is subtracted from the number formed by reversing its digits, the result is 396. What could be the original number? 
A.  654 

B.  135 

C.  852 

D.  753 
Common Information
The cost of fuel for running the engine of an army tank is proportional to the square of the speed and Rs. 64/hour for a speed of 16 kmph. Other costs amount to Rs. 400/hour. The tank has to make a journey of 400 km at a constant speed.
Q7. 
Common Information Question: 1/2 The most economical speed for this January is: 
A.  10 kmph 

B.  20 kmph 

C.  35 kmph 

D.  40 kmph 
Q8. 
Common Information Question: 2/2 The total cost for the journey at this most economical speed is: 
A.  Rs 6,000 

B.  Rs 8,000 

C.  Rs 10,000 

D.  Rs 11,000 
Q9. 
$A$ and $B$ throws one dice for a stake of Rs 11, which is to be won by the player who first throws a six. The game ends when the stake is won by $A$ or $B$. If $A$ has the first throw, then what are their respective expectations? 
A.  5 and 6 

B.  6 and 5 

C.  11 and 10 

D.  10 and 11 
Q10. 
On January 1, 2004 two new societies $s_1$ and $s_2$ are formed, each $n$ numbers. On the first day of each subsequent month, $s_1$ adds $b$ members while $s_2$ multiples its current numbers by a constant factor $r$. Both the societies have the same number of members on July 2, 2004. If $b = 10.5n$, what is the value of $r$? 
A.  2 

B.  1.9 

C.  1.8 

D.  1.7 