A man earn 45% interest on a sum.If he had invested for 3 more year then ratio of amount bgot to amount invested becomes 8:5
Answers
Answer:
in 9 Years he got 45 % interest on sum at 5% per annum
Step-by-step explanation:
A man earn 45% interest on a sum.If he had invested for 3 more year then ratio of amount bgot to amount invested becomes 8:5
Let say Amount invested = 5P
Rate of intereset = r % per Annum
Time = T Years ( in which he got 45% interest)
Interest = Principle * rate of Interest * Time / 100
=> (45/100) * 5P = 5P * r * T/100
=> rT = 45
If he invested 3 more years so
Time = T + 3 Years
Amount got / Amount Invested = 8/5
=> (Principle + interest)/Principle = 8/5
=> ( 5P + interest) /5P = 8/5
=> 5P + Interest = 8P
=> Interest = 3P
3P = 5P * r * (T+3)/100
=> 60 = rT + 3r
rT = 45
=> 60 = 45 + 3r
=> 3r = 15
=> r = 5
rate of interest = 5% per annum
rT = 45
=> 5 T = 45
=> T = 9 years
in 9 Years he got 45 % interest on sum at 5% per annum