Ex 8.3, 1 (b) - Rs 18,000 for 2 1/2 years at 10% compounde annually

Ex 8.3, 1 (b) - Chapter 8 Class 8 Comparing Quantities - Part 2
Ex 8.3, 1 (b) - Chapter 8 Class 8 Comparing Quantities - Part 3 Ex 8.3, 1 (b) - Chapter 8 Class 8 Comparing Quantities - Part 4 Ex 8.3, 1 (b) - Chapter 8 Class 8 Comparing Quantities - Part 5

Learn in your speed, with individual attention - Teachoo Maths 1-on-1 Class


Transcript

Question 1 1 (b) Calculate the amount and compound interest on (b) Rs 18,000 for 2 1/2 years at 10% per annum compounded annually. Given, Principal = 18,000 Time (n) = 2 1/2 years Rate (R) = 10 % per Annum. Since n is in fraction, we use the formula. Compound interest for 2 1/2 years = Compound interest for 2 years + Simple interest for 1/2 𝑦𝑒𝑎𝑟. Compound interest for 2 years P = 18,000 N = 2 R = 10% Amount = P (1+𝑅/100)^𝑛 Putting values = 18,000 (1+10/100)^2 = 18000 (1+1/10)^2 = 18000 ((10 + 1)/10)^2 = 18000 (11/10)^2 = 18000 × 121/100 = 180 × 121 = 21,780 Since Amount = Principal + Interest 21,780 = 18000 + Interest 21,780 − 18,000 = Interest 3780 = Interest Interest = 3780 ∴ Interest for 2 years = Rs 3780 & Amount after 2 years = Rs 21780 Simple interest for the next 𝟏/𝟐 year Principal will be the amount after 1 year P = 21,780 R = 10% T = 1/2 year Interest = (𝑃 ×𝑅 × 𝑇)/100 = (21780 × 10 × 1/2)/100 = (21780 × 10)/(2 × 100) = 21780/2 = 1089 ∴ Simple interest for next 1/2 year = Rs 1089 Now, Interest for 2 1/2 years = Compound interest for 2 years + Simple Interest for 1/2 year = 3780 + 1089 = 4869 Amount = Principal + interest = 18000 + 4869 = 22869 ∴ Amount = Rs 22,869 & Interest = Rs 4,869

Ask a doubt
Davneet Singh's photo - Co-founder, Teachoo

Made by

Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 13 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.