At what time between 7 and 8 O’clock will the hands of

At what time between 7 and 8 O’clock will the hands of a clock be at right angle?

Given that , H = 7
We know that ,The two hands of the clock will be at right angles between H and (H + 1) O’clock at minutes past H O’clock

= (5H ± 15)	12
	11

=	(5 x 7 ± 15)	12
		11

{ ∴ Taking + ve and - ve sign respectively , we get }

= 21	9	and 54	6
	11		11

∴ The hands of a clock are at right angle at

21	9	minutes past 7 and, 54	6	minutes past 7 O' clock.
	11		11