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SSC CHSL Previous Paper 116 (Held On: 17 March 2020 Shift 3)

Option 1 : ₹ 8816.97

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100 Questions
200 Marks
60 Mins

**Given **

Principal = Rs 8000

Rate of interest = 6.5% per month

**Formula Used **

Amount = principal(1 + R/100)^{t}

**Calculation**

⇒ Amount = 8000[1 + 6.5/(12 × 100)]^{18}

⇒ Amount = 8000(1.0054)^{18}

⇒ Amount = 8000(1.1021) = 8816.97

∴ The amount he will get at the end of 18 months is Rs 8816.97

We know that, by Binomial thorem,

(1 + r)^{n} ≈ 1 + nr + n(n - 1)/2 × r^{2} + ...

Monthly interest rate, r = (6.5/12)%

Now, we can calculate the amount = 8000 × {1 + 18 × (6.5/12)% + (18 × 17)/2 × [(6.5/12)%]^{2}}

Amount ≈ 8000 × {1 + 0.097 + 0.003}

Amount ≈ 8000 × 1.1 ≈ 8800

So, from the options, we can conclude that Rs 8816.97 will be the correct solution.

__Important Points__

Note that, in doing the second method, we only need to know, the binomial theorem, a basic two-power calculation to get the solution that is nearest to our required actual solution.