12,000 is invested for 1.5
years at C.I. If 15,972 is received at the end of this period,find the rate of interest per annum.
Answers
Answer:R = 21 %
R = 20.64 %
Step-by-step explanation:
Let say rate of interest = R
Interest for 1st Year = 12000 * R * 1 /100 = 120 R
Amount after 1 years = 12000 + 120R
interest for next 1/2 years = (12000 + 120R) * (1/2) R /100
= (120 + 1.2R)R/2
= 60R + 0.6R²
120 R + 60R + 0.6R² = 15972 - 12000
=> 0.6R² + 180R = 3972
=> R² + 300R = 6620
=> R² + 300R - 6620 = 0
=> R = 20.64 %
But if We calculate
Amount = P (1 + R/100)ⁿ
=> 15972 = 12000 ( 1 + R/100)^(3/2)
=> 1.331 = ( 1 + R/100)^(3/2)
=> 1.1 = √(1 + R/100)
=> 1.21 = 1 + R/100
=> R/100 = 0.21
=> R = 21 %
Answer:
R = 21 %
R = 20.64 %
Step-by-step explanation:
Let say rate of interest = R
Interest for 1st Year = 12000 * R * 1 /100 = 120 R
Amount after 1 years = 12000 + 120R
interest for next 1/2 years = (12000 + 120R) * (1/2) R /100
= (120 + 1.2R)R/2
= 60R + 0.6R²
120 R + 60R + 0.6R² = 15972 - 12000
=> 0.6R² + 180R = 3972
=> R² + 300R = 6620
=> R² + 300R - 6620 = 0
=> R = 20.64 %
But if We calculate
Amount = P (1 + R/100)ⁿ
=> 15972 = 12000 ( 1 + R/100)^(3/2)
=> 1.331 = ( 1 + R/100)^(3/2)
=> 1.1 = √(1 + R/100)
=> 1.21 = 1 + R/100
=> R/100 = 0.21
=> R = 21 %