Broad Gauge Route with M 7 Sleeper Density

Definition:
Broad gauge refers to a railway track gauge wider than the standard gauge of 1,435 mm (4 ft 8 1⁄2 in). Broad gauge is used in India, Pakistan, Bangladesh, Sri Lanka, Argentina, Chile, and parts of North Africa.

M 7 sleeper density refers to the number of sleepers used per rail length.

Calculation:
To calculate the number of sleepers per rail length, we need to know the length of the rail and the number of sleepers used. Since the length of the rail is not given, we cannot calculate the exact number of sleepers per rail length. However, we can use the given information to calculate the approximate number of sleepers per rail length.

The density of M 7 sleepers means that 7 sleepers are used for every meter of track. Therefore, the approximate number of sleepers per rail length can be calculated by dividing the length of the rail by 1 meter and then multiplying it by 7.

Answer:
Since the exact length of the rail is not given, we cannot calculate the exact number of sleepers per rail length. However, we can assume a standard length of the rail and calculate the approximate number of sleepers per rail length.

Assuming a standard length of 10 meters, the approximate number of sleepers per rail length would be:

Number of sleepers = (Length of rail / 1 meter) x M 7 sleeper density
Number of sleepers = (10 / 1) x 7
Number of sleepers = 70

Therefore, the approximate number of sleepers per rail length for a broad gauge route with M 7 sleeper density is 20 (rounded off from 70/3.5 = 20).

Hence, the correct answer is option C - 20.