Q26. 
$N$ persons stand on the circumference of a circle at distinct points. Each possible pair of persons, not standing next to each other, sings a twominute song one pair after the other. If the total time taken for singing is 28 minutes, what is $N$? 
A.  5 

B.  7 

C.  9 

D.  4 
Q27. 
A small confectioner bought a certain number of pastries flavoured pineapple, mango and blackforest from the bakery, giving for each pastry as many rupees as there were pastry of that kind; altogether he bought 23 pastries and spent Rs 211; find the number of each kind of pastry that he bought, if mango pastry are cheaper than pineapple pastry and dearer than blackforest pastry. 
A.  {10, 9, 4} 

B.  {11, 9, 3} 

C.  {10, 8, 5} 

D.  {11, 8, 4} 
Q28. 
How many subsets of {1, 2, 3, ... , 11} contains at least one even integer? 
A.  1900 

B.  1964 

C.  1984 

D.  2048 
Q29. 
A saint has a magic pot. He puts one gold ball of radius 1mm daily inside it for 10 days. If the weight of the first ball is 1 g and if the radius of a ball inside the pot doubles every day, how much gold has the saint made due to his magic pot? 
A.  \(\left(\dfrac{2^{30}69}{7}\right)\) gm 

B.  \(\left(\dfrac{2^{30}+69}{7}\right)\) gm 

C.  \(\left(\dfrac{2^{30}71}{7}\right)\)gm 

D.  \(\left(\dfrac{2^{30}+71}{7}\right)\)gm 
Q30. 
The sum of the reciprocals of the ages of two colleagues is five times the difference of the reciprocals of their ages. If the ratio of the products of their ages to the sum of their ages is $14.4 : 1$, the age (in years) of one of the colleagues must be between (both inclusive). 
A.  20 and 23 

B.  23 and 26 

C.  26 and 30 

D.  30 and 35 