# A train crosses a platform and a tunnel in 18 and 32 seconds respectively. The speed of the train and length of the train are 45 km/hr and 140 metres

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A train crosses a platform and a tunnel in 18 and 32 seconds respectively. The speed of the train and length of the train are 45 km/hr and 140 metres respectively. Find that the length of the platform is approximately what percent less than the length of tunnel?
1. 72%
2. 67%
3. 82%
4. 61%
5. 51%

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Correct Answer - Option 2 : 67%

Given:

The speed of the train = 45 km/hr.

The length of the train = 140 meters.

Formula used:

Distance = Speed × Time

Concept used:

To convert km/hr. to m/s, multiply by 5/18.

Calculation:

Speed of train = 45 × (5/18)

⇒ 25/2 m/s

According to the question:

Length of platform = [18 × (25/2) – 140]

⇒ 225 – 140

⇒ 85 m

Length of tunnel = [32 × (25/2) – 140]

⇒ 400 – 140

⇒ 260 m

Now, Required percentage = [{(260 – 85)/260} × 100]

⇒ (175/260) × 100

⇒ 67.30%

⇒ 67% (approximately)