At what time between 7 and 8 o'clock will the hands of a clock be in the same straight line but, not together?
A. 5 min. past 7
B. $$5\frac{2}{{11}}$$ min. past 7
C. $$5\frac{3}{{11}}$$ min. past 7
D. $$5\frac{5}{{11}}$$ min. past 7
Answer: Option D
Solution (By Examveda Team)
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
$$\eqalign{ & = \left( {\frac{{60}}{{55}} \times 5} \right){\kern 1pt} \min . \cr & = 5\frac{5}{{11}}{\kern 1pt} \min . \cr & \therefore {\text{Required time}} = 5\frac{5}{{11}}{\kern 1pt} \min .{\kern 1pt} \,{\text{past}}{\kern 1pt} 7 \cr} $$
Means 180 degree