SarkariPYQ

SSC CGL 2022 PYQ — Question 63

SSC CGL - 06 Dec 2022 - Shift 2 • Quantitative Aptitude • Q63

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The population of country A decreased by p% and the population of country B decreased by q% from the year 2020 to 2021. Here 'p' is greater than ‘q’. Let 'x' be the ratio of the population of country A to the population of country B in the given year. What is the percentage decrease in 'x' from 2020 to 2021?

Show answer & explanation

Correct answer: A

Explanation

The correct answer is Option 1 i.e. 100(p−q)(100−q){{100(p-q}) \over (100-q)}.

Let's assume the population of the country A in 2020 = 100

and the population of the country B in 2020 = 100

x = 100/100 = 1

According to the question,

In 2021,

The population of A = 100(100 - p)/100 = 100 - p

The population of B = 100(100 - q)/100 = 100 - q

x = (100 - p)/(100 - q)

Percentage decrease,

[1 - (100 - p)/(100 - q)]/1 × 100

= [100 - q - 100 + p]/100 - q × 100

= 100(p−q)(100−q){{100(p-q}) \over (100-q)}