A man in a train notices that he can count 21 telephone posts in one minute. If they are known to be 50… · ABC26GN3623
Subject: General Aptitude · Chapter: Time and Distance
A man in a train notices that he can count 21 telephone posts in one minute. If they are known to be 50 metres apart, then at what speed is the train travelling?
(a)55 km/hr
(b)57 km/hr
(c)60 km/hr
(d)63 km/hr
Answer
Answer (as printed): C
Explanation
Number of gaps between 21 telephone posts $=20$. Distance travelled in 1 minute $=(50 \times 20) \mathrm{m}=1000 \mathrm{m}=1 \mathrm{km}$. $$\text { ∴ } \text { Speed }=60 \mathrm{km} / \mathrm{hr} .$$