At what time between 4 and 5 will the angel between hour hand and minute hand is same as the angel of equilateral triangle.
A. (31+10/11) past4
B. 31 minutes past4
C. 10(10/11) past4
D. (32+8/11) past4
( plzzz give the reason and solution with Explaination because I don't know how to solve it and I have many more questions like this plzzz)
Answers
Explanation:
At 4 o'clock there are 20 minutes spaces between hour and minute hands To be at right angle they should be 15 minutes spaces apart
So there are two cases :
Case I : When minute hand is 15 minute spaces behind the hour hand
To be in this position the minute hand should have to gain 20 - 15 = 5 minute spaces
Now we know that 55 minute spaces are gained in 60 minute
∴ 5 minutes spaces are gained in
55
60
×5=5
11
5
min
Hence they are at right angle at 5
11
5
min past 4
Case II : When minute hand is 15 min spaces ahead of hour hand
To be in this position the minute hand should have to gain 20 + 15 = 35 minute spaces
Now we know that 55 minute spaces are gained in 60 minute
∴ 35 minute spaces will be gained in
55
60
×35=38
11
2
minute
Hence they are at right angle at 38
11
2
min past 4