Aptitude - Clock

Answer: Option E

Explanation:

When the hands of the clock are in the same straight line but not together, they are 30 minute spaces apart.

At 7 o'clock, they are 25 min. spaces apart.

Minute hand will have to gain only 5 min. spaces.

55 min. spaces are gained in 60 min.

5 min. spaces are gained in		60	x 5	min	= 5	5	min.
		55				11

Required time = 5	5	min. past 7.
	11

Answer: Option A

Explanation:

At 5 o'clock, the hands are 25 min. spaces apart.

To be at right angles and that too between 5.30 and 6, the minute hand has to gain (25 + 15) = 40 min. spaces.

55 min. spaces are gained in 60 min.

40 min. spaces are gained in		60	x 40	min	=	43	7	min.
		55					11

Required time = 43	7	min. past 5.
	11

Answer: Option C

Explanation:

Angle traced by hour hand in	13	hrs =		360	x	13		º	= 130º.
	3			12		3

Angle traced by min. hand in 20 min. =		360	x 20		º	= 120º.
		60

Required angle = (130 - 120)º = 10º.

Answer: Option E

Explanation:

Angle traced by hour hand in	21	hrs =		360	x	21		º	=	157	1	º
	4			12		4					2

Angle traced by min. hand in 15 min. =		360	x 15		º	= 90º.
		60

Required angle =		157	1		º	- 90º = 67	1	º
			2				2

Answer: Option C

Explanation:

Angle traced by hour hand in 12 hrs. = 360º.

Angle traced by it in	11	hrs =		360	x	11		º	= 110º.
	3			12		3

Angle traced by minute hand in 60 min. = 360º.

Angle traced by it in 40 min. =		360	x 40		º	= 240º.
		60

Required angle (240 - 110)º = 130º.