Let the original sum be $P$. Compound Interest (CI) for 3 years at 8% per annum is Rs. 1,94,784. The amount A after 3 years is given by $A = P(1 + R/100)^n$, where $R=8\%$ and $n=3$ years. $A = P(1 + 8/100)^3 = P(1.08)^3$. CI = $A - P = 1.259712$. CI = $P(1.259712 - 1) = P(0.259712)$. Given CI = 194784. $194784 = P \times 0.259712$. $P = 194784 / 0.259712$. To find P, we can test round numbers or perform the division. A calculation shows $194784 / 0.259712 = 750000$. So, the original sum $P = 750000$.Now calculate the simple interest (SI) on a new principal $P'$, for time $T'$, and rate $R'$. New principal $P' = \frac{9}{10}$ of the original sum $P = \frac{9} {10} \times 750000 = 9 \times 75000 = 675000$. Time $T'$ = same time as CI, which is 3 years. New rate $R' = 1\frac{1}{2}$ times the original rate = $1.5 \times 8\% = 12\%$. Simple Interest SI = $ \frac{P' \times R' \times T'}{100}$. SI = $ \frac{675000 \times 12 \times 3}{100}$. SI = $6750 \times 12 \times 3 = 6750 \times 36$. $6750 \times 36 = 6750 \times (30 + 6) = 6750 \times 30 + 6750 \times 6 = 202500 + 40500 = 243000$. Alternatively, $6750 \times 36 = (27000/4) \times 36 = 27000 \times 9 = 243000$.The simple interest is Rs. 2,43,000.