Q1:

S₁: Calcutta unlike other cities kepts its trams.

P : As a result there horrendous congestion.

Q : It was going to be the first in South Asia.

R : They run down the centre of the road

S : To ease in the city decided to build an underground railway line.

S₆: The foundation stone was laid in 1972.

The Proper sequence should be:

Question

Q1:

S₁:	Calcutta unlike other cities kepts its trams.
P :	As a result there horrendous congestion.
Q :	It was going to be the first in South Asia.
R :	They run down the centre of the road
S :	To ease in the city decided to build an underground railway line.
S₆:	The foundation stone was laid in 1972.

The Proper sequence should be:

Ordering of Sentences