Aptitude - Clock - Discussion

It's very simple.

As it was mentioned opposite(180°).
180° = (11/2*m)-30(hr),
180° = (11/2*m)-30(4),
m = 600/11,
m = 54.5454.

When to use (11/2) *m -30H & 30H - (11/2) *m?

Kindly explain.

Step 1: Fix the hour hand to the starting time given i.e. here in this case at 4.
Step 2: Count the min spaces for the min hand to be in a straight line but in the opposite direction of 4 and denote it by m.
Step 3: In this case, the min hand has to be on 10 to be in the opposite side of 4 hence m = 50 min spaces.
Step 4: Use the formula: 12m/11 = 12*50/11 = 600/11 = 54 6/11.

Guys, how do we get the 20 spaces? Anyone, explain to me.

At 4'O clock ---------> 20 mins spaces.

To be in the opposite direction, they must have 30 mins spaces.

So, clock follows the only clockwise direction that's why it has to gain 50 mins spaces apart to be in the opposite direction.

55 mins spaces ----------------> 60 mins.
50 mins spaces---------------> 60/55*50 = 54(6/11)min.

So, the answer is 54(6/11)min past 4.

Can someone please explain this to me in detail?

-> Imagine if both the hands are 12 i.e time is 12:00 then at 1:00 -> Hour hand will be at 1:00 .

-> Minute hand will be at 12 again.Therefore the space gained by minute hand over hour hand is 55 min in 1 hour,i.e. 55 min in 60 min i.e logical data which is used in all problems.

-> Coming to the problem,the hour hand is at 4:00 and minute hand is at 12,therefore to cross hour hand the minute hand has to gain 20 min spaces i.e it means it has to move 20 min forward.

-> Between 4:00 and 5:00 if the hour hand and minute have to be in opposite directions,then hour hand will be at 5:00 and minute hand will be 55 then it has gain 30 minutes more.

-> Totally it has to gain 20+30=50 minutes.

-> If 55->60 then 50->? Ans = 54 6/11 min past 4 they will be in opposite directions.

How its 55min?

Initially its 12:00am hour and min hand makes 0° after an hour i.e 1:00am hour hand travels 5 min and minute hand travels 60 min so difference between hour and min hand is 55 min.

Between 4 and 5, the minute hand to move 20 min in right half of circle (watch) from the initial point that is 12 here.

And 30 minutes from 4 in another side to go in opposite direction. So total is 20+30=50.

Use this formula that is Min=60/11 * (Hr+6)

If Hr 1 to 5 make addition
If Hr 6 to 12 make subtraction.

Like Q 4 to 5 clock in opposite directions case

Min = 60/11 * (4+6)
= 60/11 * 10
= 600/11
= 54 6/11. Min. Past.