In one and a half hours, the minute hand of a clock rotates through an angle of
90o
180o
640o
450o
540o
Correct answer is E
1 hr = 60 mins, 60 mins = 360°
30 mins = \(\frac{360^o}{1}\) × \(\frac{30}{60}\)
= 180°
90 mins = 360° + 180°
= 540°