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SSC GD 2021 PYQ — Question 69

SSC GD Constable (English) - 23rd November 2021 Shift 1 • Quantitative Aptitude • Q69

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The compound interest on a certain sum at a rate of 12% per annum for 2 years is ₹1,590. The simple interest on the same sum for double the time period and at half the interest rate per annum is

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Correct answer: A

Explanation

The correct answer is option 1 i.e. ₹1500

SI = P[(1 + R/100)T - 1]

1590 = P[(1 + 12/100)2 - 1]

1590 = P[(1 + 3/25)2 - 1]

1590 = P[(28/25)2 - 1]

1590 = P[(784/625) - 1]

1590 = P[159/625]

P = 1590×625159\dfrac{1590 × 625}{159}

P = 6250

Now

SI = P×R×T100\dfrac{P × R × T}{100}

= 6250×6×4100\dfrac{6250 × 6 × 4}{100}

= 1500