A Cistern can be filled by a tap in 4 hours while it can be emptied by another tap in 9 hours. If both the taps are opened simultaneously then after how much time will the cistern get filled?
(A) 6.5 hrs
(B) 7.2 hrs
(C) 2.5 hrs
(D) 3 hrs
Two pipes A and B can fill a tank in 3 hours and 5 hours. Then, if all three are open, the tank is filled in 30 hours. Find in how many hours a third pipe will empty the tank?
(A) 4 hours
(B) 2 hours
(C) 8 hours
(D) 6 hours
If the square root of 841 is 29, then 0.00000841 is equal to :
(A) 0.00029
(B) 0.29
(C) 0.029
(D) 0.0029
The sum of the squares of 3 consecutive positive numbers is 365. The sum of the numbers is
(A) 36
(B) 45
(C) 30
(D) 33
A man can swim at the rate of 3 km/hr. in still water. Then, if speed of the stream is 2 km/hr., then in what time he will cover a total distance of 5 km in with the stream and against the stream?
(A) 6 hours
(B) 6.5 hours
(C) 4 hours
(D) 5 hours
A boat running upstream takes 7 hours and 40 minutes to cover a certain distance while it takes 5 hours to cover the same distance downstream. What is the ratio between the speed of the current and speed of the boat respectively?
(A) 13: 4
(B) 17: 4
(C) 19: 4
(D) 4: 19
LCM of two numbers is 2079 and their HCF is 27. If one of the numbers is 189, the other number is
(A) 297
(B) 584
(C) 189
(D) 216
a and b are two whole numbers and c is their HCF, then the LCM of those two numbers is
(A) ab/c
(B) abc
(C) bc
(D) ac/b
If the numerator of a fraction is increased by 250% and the denominator is increased by 400%. The resultant fraction is7/19 . What is the original fraction?
(A) 5/8
(B) 10/19
(C) 18/23
(D) 15/17
Let p, q and r be the fraction such that p<q<r. If r is divided by p, the result is 5/2, which exceeds q by 7/4. If
(A) 2/3
(B) 1/2
(C) 1/3
(D) 1/6
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