13. A certain sum of money amounts to R6,500 in 3 years and 5,750 in 1

1.	13. A certain sum of money amounts to R6,500 in 3 years and 5,750 in 1, yearsrespectively . Find the principal and the rate percent.
Answer» Amount 3 years = 6500Amount in1.5 years = 5750 interest in 1.5 years = 6500 - 5750 = 750interest in 3(=1.5×2) years = 750×2 = 1500Principal = 6500 - 1500 = 5000 1500 = Ptr/100⇒ 1500 = 5000×3×r/100⇒ r = (1500×100)/(5000×3) = 10%

13. A certain sum of money amounts to R6,500 in 3 years and 5,750 in 1, yearsrespectively . Find the principal and the rate percent.

Answer»

Amount 3 years = 6500Amount in1.5 years = 5750

interest in 1.5 years = 6500 - 5750 = 750interest in 3(=1.5×2) years = 750×2 = 1500Principal = 6500 - 1500 = 5000

1500 = Ptr/100⇒ 1500 = 5000×3×r/100⇒ r = (1500×100)/(5000×3) = 10%