Ques:- There is a leak in the bottom of a cistern. When the cisternis thoroughly repaired, it would be filled in 3 ? hours. It now takes half an hour longer. If the cistern is full, howlong will the leak take to empty the cistern?
A. 24 hours
B. 28 hours
C. 21 hours
D. 27 hours
E. None of these
Ques:- A number is divisible by 11 if the difference between the sum of the digits in odd and even places respectively is
A. a multiple of 3
B. a multiple of 5
C. zero or a multiple of 7
D. zero or a multiple of 11