Note: Count the number of days for 1990 on wards to get 0 odd day. Year 1990 1991 1992 1993 1994 1995 Odd days 1 1 2 1 1 1 = 7 or 0 odd day. :. Calendar for 1990 is the same as for the year 1996.

Note: Since any in March is the same day of the week as the corresponding date in November of that year, so the same day falls on 5th November.

Note: Angle traced by hour hand in 12 hrs = 360° Angle traced by it in` 11/3` hrs` = (360/12 xx 11/3)^° = 110^°` Angle traced by minute hand in 60 min.` = 360^°` Angle traced by it in 40 min` = (360/60 xx 40)^° = 240^° :. Required angle` = (240 - 110)^° = 130^°`

Note: Angle traced by min. hand in `17/2` hrs` = (360/12 xx 17/2)^°` `= 255^°` Angle traced by min. hand in 30 min.`= (360/60 xx 30)^°` `= 180^°` :. Required angle` = (255 - 180)^°` `= 75^°`

Note: Angle traced by hour hand in `13/2` hrs` = (360/12 xx 13/3)^°` `= 130^°` Angle traced by min. hand in 20 min.` = (360/60 xx 20)^°` `= 120^°` :. Required angle` = (130 - 120)^° = 10^°`

Note: The hands of a clock coincide 11 times in every 12 hours (Since between 11 and 1, they coincide only once, i,e at 12 o, clock). :. The hands coincide 22 times in a day.

Note: In 12 hours the hand coincide or are in opposite direction 22 times. :. In 24 hours the hands coincide or are in opposite direction 44 times a day.

Note: In 12 hours they are at right angles 22 times. :. In 24 hours they are at right angles 44 times

Note: The hands of a clock point towards each other 11 times in every 12 hours (Because between 5 and they point towards each other at 6 0'clock only). So, in a day the hands points towards each other 22 times.

Note: At 5 o'clock, the minute hand is 25 min.spaces apart. To be coincident, it must gain 25 min.spaces. 55 min are gained in 60 min 25 min are gained in` (60/55 xx 25)` min `= 27 3/11` min