1/7 - 1/14 = 1/14
14 minutes
A pipe can fill a cistern in 7 minutes whereas the cistern when fill can be emptied by a leak in 14 minutes. When both pipes are opened, find when the cistern will be full?
Options:
(A) 17
(B) 16
(C) 70
(D) 14
(E) 12
(D)

Minimum age = Average - 1 Standard deviation = 10 - 8 = 2
Maximum age = average + 1 Standard deviation = 10+ 8 = 18
Maximum number of different ages of the applicants = 18 - 2 + 1 = 17
The average age of applicants for a new job is 10, with a standard deviation of 8. The hiring manager is only willing to accept applicants whose age is within one standard deviation of the average age. Assuming that all applicants' ages are integers and that the endpoints of the range are included, what is the maximum number of different ages of the applicants?
Options:
(A) 8
(B) 16
(C) 17
(D) 18
(E) 34
(C)

Simple interest = (18000 * 4 * 15)/100 = Rs. 10800
Amount = P + I = 18000 + 10800 = Rs. 28800
What amount does Kiran get if he invests Rs. 18000 at 15% p.a. simple interest for four years?
Options:
(A) 3888
(B) 26989
(C) 26700
(D) 28800
(E) 2879
(D)