Ex 7.3

Chapter 7 Class 8 Comparing Quantities
Serial order wise

### Transcript

Question 9 Find the amount which Ram will get on Rs 4096, if he gave it for 18 months at 12 % 1/2 per annum, interest being compounded half yearly. Given, Principal (P) = 4096 Rate (R) = 12 1/2 Per annum = 25/2 % Per annum = 25/2 × 1/2 % Per half year = 25/4 % Per half year Time (n) = 18 months = 18/6 half years = 3 half years Amount (A) = P (1+𝑅/100)^𝑛 = 4096 (1+(25/4)/100)^3 = 4096 (1+25/(4 × 100))^3 = 4096 × (1+1/(4 × 4))^3 = 4096 × (1+1/16)^3 6 Months = 1 Half year 1 Month = 1/6 Half Year 18 Months = 18 × 1/6 half year = 4096 × ((16 + 1)/16)^3 = 4096 × (17/16)^3 = 4096 × (17 × 17 × 17)/(16 × 16 × 16) = 4096 × (289 × 17)/(256 × 16) = 4096 × 4913/4096 = 4913 ∴ The amount he will get is Rs 4913

#### Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 14 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.