Aptitude - Clock - Discussion

Thanks @Harry.

Superb formula. Thanks alot.

Dear sir,

Please prove formula.

If the minute hand is present before hour hand then use theta = 11/2min-30hr.

Like that hour hand is before minute hand theta = 30hr-11/2hr.

Use it you will get exact solution.

Direct formula:

6*x - 90 = 30(y + x/60);

Where y = 5 hr.

So 6x = 30(5 + x/60) + 90;

x = 43(7/11)min. past 5.

Sorry @Riddilavan your formula may wrong if you solve this question.

How many minutes after 7 o'clock and before 8'o clock will the hands of the clock be in opposite direction?

Thanks @Harry.

At what time between 5 and 60' clock the hands of a clock will make an angle of 40%?

Anyone, explain the answer.

Since for 1 hour, the minute's arm move 360 degrees. And for each hour arm move 30 degrees.

Hence for every 1 degree move the minute's arm move 12 degrees.

When the time is 5 : 30 the angle between the min arm and hour arm is 15 degree.

Our target to find a time when the angle is 90 degree.

For this, we solve the equation :12x - x + 15 = 90.

From here we get x = 75/11.

30 degree = 1 hour.

75/11 degree = 1/30 * 75/11 = 5/22hours = 300/22min.

Hence final time is 30 + 300/22 = 480/22 min from 5 o'clock. (we add 30 because we have considered the arms move from 5:30).

I was getting confused in using the formula.

But your answer helps me, Thankyou @Prashanth.