At which time number of minutes elapsed since midnight is nine times the number of minutes before noon? · ABC26GN5191
Subject: General Aptitude · Chapter: Clocks · Exam: R.R.B. 2006
At which time number of minutes elapsed since midnight is nine times the number of minutes before noon?
(a)8.30 a.m.
(b)6.56 a.m.
(c)9.46 a.m.
(d)10.48 a.m.
Answer
Answer (as printed): D
Explanation
Let the required time be $x$ minutes after midnight. Duration from 12 midnight to 12 noon $$\begin{aligned} & =12 \mathrm{hrs}=(12 \times 60) \mathrm{min}=720 \mathrm{min} . \\ & \text { So, } x=9(720-x) \Rightarrow 10 x=6480 \Rightarrow x=648 . \end{aligned}$$ Hence, required time $=648 \mathrm{min}$ after midnight = 10 hrs 48 min after midnight = 10.48 a.m.