**ML Aggarwal CBSE Solutions Class 8 Math 7th Chapter Compound Interest Exercise 7.3**

**(6) **V_{0} = Present value = 16000

V = Value after 2 years = 14440

N = 2 years

R =?

V = V_{0} [1- r/100]^{r}

Or, 14440 = 16000 (1 – r/100)^{2}

Or, 14440/16000 = (1 – r/100)^{2}

Or, (38/40)^{2} = (1- r/100)^{2}

Or, 38/40 = 1 – r/100

Or, r/100 = 1 – 38/40 = 40–38/40 = 2/40

Or, r = 2X10/4 = 5% (Ans)

**(7) **V_{0} = 80000

V = 92610

N = 3 years

V = V_{0} [1+ r/100]^{n}

Or, 92610 = 80000 [1+ r/100]^{3}

Or, 9261/8000 = (1+ r/100)^{3}

Or, (21/20)^{3} = (1+ r/100)^{3}

Or, 21/20 = 1+ r/100

Or, 21/20 – 1 = r/100

Or, 21-20/20 = r/100

Or, 1 X 5 = r

Or, r = 5% (Ans)