While travelling downstream, a man can row 16 km more in 4 hours as compared to travelling upstream. What is the speed of the stream?

In the following question two equations numbered I and II are given. You have to solve both the equations and ____
I.$$ {15\over \sqrt {x}}-{2\over \sqrt {x}}=6\sqrt {x}$$
II.$$ {\sqrt {y}\over 4}-{7\sqrt {y}\over \sqrt {12}}={1\over \sqrt {y}}$$
Give answer
(A) x>y
(B) x≥y
(C) x<y
(D) x≤y
(E) x=y or the relationship cannot be established

The strength of a school increases and decreases in every alternate year by 10 %. It started with increase in 2000, then the strength of the school in 2003 as compared to that in 2000 was : 

The Ajmer express can move at 45 km./hr. without its rake and the speed is diminished by a constant that varies as the square root of the number of wagons attached. If it is known that with 9 wagons, the speed is 30 km./hr., what is the greatest number of wagons with which the train can just move?

What is the equation of line whose slope is -1/2 and passes through the intersection of the lines x-y = -1 and 3x-2y = 0?

A sofa-set listed at ₹ 800 is sold to a retailer at successive discounts of 25% and 15% by the wholesaler. Then the cost price of the sofa-set for retailer is-

Average of ten positive numbers  is x. If each number is increased by 12%  then x is increased by

If $$ {3^{4x-y}={3^{x+y}=\sqrt{27}}}$$,  then the value of y is: