SarkariPYQ

SSC CHSL 2021 PYQ — Question 70

SSC CHSL - 12 April 2021 - Shift 3 • Quantitative Aptitude • Q70

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Comprehension:
In the following passage, some words have been deleted. Select the most appropriate option
to fill in each blank.
In the 19th century, there was an industrial revolution in Europe. As a result, millions of people
left the (1) ______ and went to work in big factories in cities. Today, it is the reverse. In several
major cities, people have started moving out. Why? They want a cleaner, (2) ______
environment. There are fewer jobs in ‘heavy’ industries like steel and power generation. (3)
______, there are more jobs in service industries like banking, tourism and food delivery.
Besides, modern transport and communications have made it easier for people to (4) ______
to work or even work from home. The result of this revolution in the 21st century will be
‘spread cities’ – cities are growing fast, but (5) ______, away from city centres and people are
choosing to live 40, 50 or 60 kilometres away.

Working together. A, B, and C can finish a piece of work in 3 hours. A finishes the same work in 8 hours and B finishes it in 6 hours. How long will it take for C alone to finish the same work?

Show answer & explanation

Correct answer: C

Explanation

The correct answer is option 3 i.e. 24 hours

The total work done, let be the LCM of 3, 8, and 6 = 24 units 

A, B, C efficiency together = 24/3 = 8 hours                                  

A's efficiency = 24/8 =  3 hours              

B's efficiency = 24/6 = 4 hours

⇒ The efficiency of C = (8 - 3 - 4) = 1 unit per day 

Number of hours taken by C to finish the work alone = 24/1 = 24 hours