Question

At what time will the minute hand and hour hand of a wall clock make one-third angle of the right angle between 8 pm and 9 pm?
Note: Select the accurate time in hours and minutes.
Incorrect answer: 0
Correct answer: +1
Options
8:49 PM
8:20 PM
8.40 PM
8:37 PM​

Answer 1

Answer:

Step-by-step explanation:

8:40 Pm

Answer 2

Answer:

At 8:40 PM the the minute hand and hour hand of a wall clock make one-third angle of the right angle between 8 pm and 9 pm.

Step-by-step explanation:

Given,a wall clock make one-third angle of the right angle between 8 pm and 9 pm.

One third of angle of the right angle means

$= \frac{1}{3} \times$90°$= \frac{90°}{3} = 30°$

Now question is

At what time between 8 and 9 o clock will the hands of the clock be at right angles?

We know in 12 hr hour hand and minutes hand complete 360° of the clock. By this calculation,we can easily found any time or degree.

Using the formula= $30H - \frac{11M}{2}$ = angle

Where H = hour

M= minutes

So,

$30 \times 8 - \frac{11M}{2}$= 30°

→240–30=$\frac{11M}{2}$

210=$\frac{11M}{2}$

M=$\frac{420}{11}$=38.18mins=40 mins (approx)

Required time is 8:40 P.M.