A train running at the speed of 60 km/hr crosses a pole in 9 seconds. What is the length of the train?

### Concept & Formula When a train crosses a stationary pole, the distance covered is equal to the length of the train. $$ \text{Length of Train} = \text{Speed} \times \text{Time} $$ ### Step-by-Step Solution * **Given:** Speed = $60$ km/hr, Time = $9$ seconds. * **Convert Speed:** Change km/hr to m/s by multiplying by $\frac{5}{18}$. * Speed = $60 \times \frac{5}{18} = 10 \times \frac{5}{3} = \frac{50}{3}$ m/s. * **Calculate Length:** Length = $\text{Speed} \times \text{Time}$ * Length = $\frac{50}{3} \times 9$ * $= 50 \times 3 = 150$ metres. * **Check Options:** $150$ metres is not among the given options (a), (b), or (c). ### Exam Strategy & Shortcut Write it all in one line before calculating to allow for easy cross-cancellation: $60 \times \frac{5}{18} \times 9$. The $9$ cancels with the $18$ to leave $2$ in the denominator. $\frac{60 \times 5}{2} = 30 \times 5 = 150$. ### Common Pitfall Choosing "Cannot be determined" simply because the calculated answer isn't present. The answer *can* be determined ($150$m), it just happens to be missing from the specific numbered options. ### Final Answer Therefore, the correct answer is **None of these**.