11.
How many times are the hands of a clock at right angle in a day?

12.
The angle between the minute hand and the hour hand of a clock when the time is 8:30, is:

13.
How many times in a day, are the hands of a clock in straight line but opposite in direction?

14.
At what time between 4 and 5 o'clock will the hands of a watch point in opposite directions?

15.
At what time between 9 and 10 o'clock will the hands of a watch be together?

16.
At what time, in minutes, between 3 o'clock and 4 o'clock, both the needles will coincide each other?

17.
How many times do the hands of a clock coincide in a day?

18.
How many times in a day, the hands of a clock are straight?

19.
A watch which gains uniformly is 2 minutes low at noon on Monday and is 4 min. 48 sec fast at 2 p.m. on the following Monday. When was it correct?

20.
A watch becomes fast by 5 minutes everyday. By what percent does it become fast ?