36.
How many times are the hour hand and the minute hand of a clock of a right angles during their motion from 1 : 00 pm to 10 : 00 pm ?

37.
Wall clock gains 2 minutes in 12 hours, while a table clock loses 2 minutes every 36 hours. Both are set right at 12 noon on Tuesday. The correct time when both show the same time next would be = ?

38.
A clock is displaying correct time at 9 am on Monday. If the clock loses 12 minutes in 24 hours, then the actual time when the clock indicates 8 : 30 pm on Wednesday of the same week is = ?

39.
A wall-clock takes 9 seconds in tinging at 9 o'clock. The time, it will take in tinging at 11 o'clock, is = ?

40.
A mechanical grandfather clock is at present showing 7 hours 40 minutes 6 seconds. Assuming that it loses 4 seconds in every hour, what time will it show after exactly $$6\frac{1}{2}$$ hours ?