Discussion

Explanation:

Length of first train = 0.108 km

Length of second train = 0.112 km.

Let the speed of second train be x. 

As the trains are moving towards each other,

$\frac{0.108+0.112}{50+x}=\frac{6}{60\times 60}$ 

∴ x = 82 km/hr.

Hence, option (d).

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