20. Барааны үнэ байгаа үнээсээ хоёр удаа дараалан тэнцу хэдзн хувиар өсөхөд анхны үнээс \( 10.25 \% \)-иар өссөн байх вэ?

Find the compound amount and the amount of interest earned by the deposit below. \( \$ 3,000 \) at \( 3.89 \% \) compounded continuously for 4 years. What is the compound amount? \( \$ \square \)

Find the compound amount and the amount of interest earned by the following deposit. \( \$ 5800 \) at \( 3.4 \% \) compounded continuously for 9 years. The future value after 9 years is approximately \( \$ \square \). (Do not round until the final answer. Then round to the nearest cent as needed.)

यदि ब्याज की दर पहले वर्ष के लिए \( 4 \% \) प्रति वार्षिक दूसरे वर्ष के लिए \( 5 \% \) वार्षिक तथा \( 6 \% \) वार्षिक तीस वर्ष के लिए है तो 10000 रू. की धनराशि पर 3 वर्ष चक्रवृद्धि ब्याज क्या होगा? \( \begin{array}{ll}\text { (1) Rs. } 1600 & \text { (2) Rs. } 1625.80 \\ \text { (3) Rs. } 1575.20 & \text { (4) Rs. } 2000\end{array} \)

During a sale, a shop offered a discount of \( 10 \% \) on the marked prices of all the items. What would a customer have to pay for a pair of jeans marked at \( \bar{₹} 1450 \) and two shirts marked at ₹ 850 each?

8000 रू. की धनराशि पर \( 15 \% \) वार्षिक दर से 2 वर्ष 4 महीने का चक्रवृद्धि ब्याज होगा, यदि ब्याज दर वार्षिक संयोजित है- \( \begin{array}{ll}\text { (1) Rs. } 2980 & \text { (2) Rs. } 3091 \\ \text { (3) Rs. } 3109 & \text { (4) Rs. } 3100\end{array} \)