241 .
What is the speed of a boat in still water?

I. The boat covers 12 km in 2 hours downstream.
II. The boat covers the same distance in 4 hours upstream.
III.The speed of the stream is one-third that of the boat in still water.
A.Only II
B. Both I and II
C. I and either II or III
D.All I, II and III
E.None of these
242 .
$\sqrt{7921} * 51 + 374 = ?^3$
A.17
B. 19
C. 21
D.23
E.None of these
243 .
A car takes 5 hrs to cover a distance of 300 km. How much should the speed in km/hr be maintained to cover the same distance in 4/5th of the previous time ?
A.60 km/hr
B. 65 km/hr
C. 70 km/hr
D.75 km/hr
E.None of these
244 .

What is the ratio of the total number of passed students to total number of students not passed for the year 2007 ?
A.3:19
B. 19:3
C. 13:131
D.131:13
E.None of these