Para-jumble (sentence arrangement): Arrange P–Q–R–S to complete the paragraph about Calcutta's trams and urban transport decisions. S1 = "Calcutta, unlike other cities, kept its trams." P = "As a result, there was 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 it, the city decided to build an underground railway line." S6 = "The foundation stone was laid in 1972." Between S1 and S6, place P–Q–R–S in a logically progressing order. Choose the correct sequence of P–Q–R–S that completes the paragraph.

Given data

• S1 states that Calcutta retained trams.
• R explains how the trams operate (centre of the road).
• P presents the consequence (congestion).
• S provides the remedy (build an underground line); Q adds its distinction (first in South Asia).

Concept/Approach
Follow cause → effect → solution → notable fact sequencing for urban planning narratives.

Step-by-step reasoning
R naturally follows S1 by describing tram alignment, a cause of bottlenecks. P states the effect: severe congestion. S introduces the decision to build an underground railway to relieve congestion. Q appends the noteworthy detail that it would be the first in South Asia, leading to S6 (foundation in 1972).

Verification
R → P forms a clear cause–effect pair; S → Q reads like decision → significance before the dated conclusion S6.

Common pitfalls
Putting Q before S mentions the "first" without first stating what is being built.

Final Answer
RPSQ