At what time between 4 & 5 will the hands of a watch point in opposite directions
Explanation:
4 o'clock, the hands of the watch are 20 min. spaces apart.
To be in opposite directions, they must be 30 min. spaces apart.
Minute hand will have to gain 50 min. spaces.
55 min. spaces are gained in 60 min
50 min. spaces are gained in 
min. or 
Required time = min. past 4.