KidsGen - the new age kids site

A Watchful Watch (Brain Teaser)

Monvenience - Transact in Convenience

A Watchful Watch

Q. Some important information leading to Sushila’s murder was given by one Sudarshan Lal. He had cultivated a habit of nothing in his diary the exact time of any strange, bizarre and unusual happening or event.

He had his way of recording time such as: If it was five minutes past seven, he would record 7:05. Or, when it was twenty minutes past one, it would be 1:20 in his dairy.

That day too, he did the same. As soon as he saw two masked men entering a neighboring house, he noted down the time. Two minutes later he heard six shots.

Later, it became known that those masked men had come to loot the house and when Sushila resisted one of them pressed the trigger and emptied the revolver on her.

The time noted by Sudarshan Lal would represent a figure in a complete square if the ‘point’ between hrs. and minutes were removed.

Another funny thing came to light. Had the reflection in the mirror of that particular time been noted and the decimal point removed, the figure would have represented two complete squares by the addition of 8 to it or subtracting 15 from it. From the above, can you tell when the first bullet was fired?

A. First bullet was fired at 10:26.


  1. The criminals entered the house at 10:24. When the decimal point is removed from it we get 1024 which is a complete square.
  2. When we add 8 and deduct 15 from the time reflected in the mirror we get complete square figures. Therefore this time is between two figures of complete squares. That means 2 complete squares of three digits have 23 as the difference. These figures are square of 11 and 12. (That is how the difference of two squares can be 11+12=23).
  3. Figure 136 meets the condition of 8 & 15. The mirror shows 1.36 (Time). Which means actual time to be 10:24. (When we deduct the time seen in the mirror from 12:00, we get the actual time).


Study in the UK