A sum of Rs. 21000 amounts to Rs. 27300 in 3 years at a certain rate percent per annum simple interest. The same sum will amount to what in 1 year at the same rate if the interest is compounded half yearly? (in nearest 1 Rs)

23153

             Sum          Amount

           21000     :     27300

                 10    :      13

SI = 3 unit

  3 = \(\frac{10 × R × 3}{100}\) ⇒ R = 10%

CI rate half yearly = \(\frac{10}{2}\) = 5%

                    5% → \(\frac{1}{20}\)

                   20          21

                 400          441

                 400 unit = 21000

                441 unit = \(\frac{21000}{400}\) × 441 = 23152.5

                                                                            = ∼ 23153