Shahrukh opened a Recurring Deposit Account in a
bank and deposited 800 per month for 18 months
If he received 15084 at the time of maturity
find the rate of interest per annum
Answers
Sum of money [ Principal ] = ₹ 800
Time = 18 months
Maturity value (M.V) = ₹ 15084
First of all find the interest, by using formula :
M.V = P×n + Interest
Interest = M.V - P×n
Interest = ₹15084 - 800 × 18
Interest = ₹684
Now , use the Interest formula :
Interest = P × n(n+1) × Rate/2 ×12 × 100
684 = 800 × 18(19) × Rate/ 2×12×100
Rate = 684×2×12×100/18×19×800
After calculation....
Rate% = 6%
I hope it will help u...
Amount deposited by Shahrukh per month = ₹ 800
We know that
No. of months (n) = 1 ½ = 3/2 × 12 = 18 months
We know that
Total principal for one month = 800 × [x (x + 1)]/ 2
Substituting the value of x
= 800 × (18 × 19)/ 2
By further calculation
= ₹ 136800
Interest = PRT/ 100
Substituting the values
= (136800 × r × 1)/ (100 × 12)
So we get
= 114r
So the amount of maturity = P × x + SI
15084 = 800 × 18 + 114r
By further calculation
114r = 15084 – 14400
114r = 684
r = 684/114 = 6%
Hence, the rate of interest per annum is 6%.