Subject: General Aptitude · Chapter: Time and Distance · Exam: · Marks: · Difficulty:
A plane flying north at 500 mph passes over a city at 12 noon. A plane flying east at the same altitude passes over the same city at 12 : 30 P.M. The plane is flying east at 400 mph. To the nearest hundred miles, how far apart are the two planes at 2 P.M.?
(a)600 miles
(b)1000 miles
(c)1100 miles
(d)1200 miles
(e)1300 miles
Answer
Answer (as printed): D
Explanation
Distance covered by the first plane till 2 P.M., i.e., in 2 $\mathrm{hrs}=(500 \times 2)$ miles $=1000$ miles. Distance covered by the second plane till 2 P.M., i.e., in $$1 \frac{1}{2} \mathrm{hrs}=\left(400 \times \frac{3}{2}\right) \text { miles }=600 \text { miles. }$$ ∴ Required distance $$\begin{aligned} & =A B=\sqrt{(1000)^{2}+(600)^{2}} \\ & =\sqrt{1000000+360000} \end{aligned}$$
Explanation as extracted from the printed page; notation may be imperfect.