A pipe can fill a tank in 16 hours. Due to a leak in the bottom,it is filled in 24 hours. If the tank is full, how much time will the leak take to empty it ?
Options:
(A) 12 hrs
(B) 24 hrs
(C) 36 hrs
(D) 48 hrs
(E) 42 hrs
Answer and stream of consciousness: (D)
Stream of consciousness: Time taken by leak to empty tank = 1/(1/16-1/24) = 48 hrs

How much is 80% of 40 is greater than 4/5 of 25?
Options:
(A) 22
(B) 77
(C) 15
(D) 12
(E) 88
Answer and stream of consciousness: (D)
Stream of consciousness: (80/100) * 40 (4/5) * 25
32 - 20 = 12

The number N is 5,2H4, where H represents the ten's digit. If N is divisible by 9, what is the value of H?
Options:
(A) 1
(B) 3
(C) 5
(D) 7
(E) 9
Answer and stream of consciousness: (D)
Stream of consciousness: If the number is divisible by 9, it must also be divisible by 3. Only 7 yields such a number.

How much time will it take for an amount of 500 to yield 100 as interest at 5% per annum of simple interest?
Options:
(A) 3 year
(B) 4 year
(C) 6 year
(D) 5 year
(E) 7 year
Answer and stream of consciousness:
(B)
Stream of consciousness: Time = (100 x 100)/(500 x 5) years = 4 years.