# Aptitude - Clock - Discussion

Discussion Forum : Clock - General Questions (Q.No. 16)

16.

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

Answer: Option

Explanation:

At 3 o'clock, the minute hand is 15 min. spaces apart from the hour hand.

To be coincident, it must gain 15 min. spaces.

55 min. are gained in 60 min.

15 min. are gained in | 60 | x 15 | min | = | 16 | 4 | min. | |

55 | 11 |

The hands are coincident at 16 | 4 | min. past 3. |

11 |

Discussion:

31 comments Page 1 of 4.
Penjor said:
2 years ago

How 15 min spaces at 3 o clock? Anyone explain it for me.

OVI said:
3 years ago

Can anyone explain briefly?

Shruti said:
3 years ago

55 min is there because.

In one hour (60 min), the minute hand is 55 min ahead of the hour hand.

In one hour (60 min), the minute hand is 55 min ahead of the hour hand.

Pavan said:
3 years ago

Thank you @sai.

Grump said:
4 years ago

Here, min space refers to the displacement of the minute hand, w.r.t y o' clock, in forms of mins(minute hand mins) where y = 3.

So min space = 15(5, 10, 15 - 1, 2, 3)

Visualize relative speed. There are two trains. One is goods train 15 km away travelling at 5/60 km per min.

And there is another train which is travelling at 1 km per minute.

Relative speed = (1-5/60)kmph.

= 55/60 = 11/12.

time = distance/speed = 15/(11/12)min = 180/11 min = 16 + 4/11 min.

So min space = 15(5, 10, 15 - 1, 2, 3)

Visualize relative speed. There are two trains. One is goods train 15 km away travelling at 5/60 km per min.

And there is another train which is travelling at 1 km per minute.

Relative speed = (1-5/60)kmph.

= 55/60 = 11/12.

time = distance/speed = 15/(11/12)min = 180/11 min = 16 + 4/11 min.

Nancy said:
4 years ago

How to find 15min space?

Mohan said:
4 years ago

How 15 min space comes? if we consider 3 o clock. Please explain.

Sumi said:
4 years ago

Thanks all for explaining.

Harshitha said:
4 years ago

Thanks to all for explaining, I understand the answer.

Raju said:
5 years ago

Let M for a minute, T1 for the starting hour and Y for a nangle.

Then the formula be M= 2/11(T1*30- 0r + Y).

2/11(3*30+-0) because coincide means angle is zero.

2*90/11.

180/11.

16 4/11 answer.

Then the formula be M= 2/11(T1*30- 0r + Y).

2/11(3*30+-0) because coincide means angle is zero.

2*90/11.

180/11.

16 4/11 answer.

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