Question

The amount of a sum of money of 4 years is 620, and the amount of 6 years is 680, then find the principle and rate of interest

Answer 1

p = 500 , r = 6%

Step-by-step explanation:

there is no mention of whether the interest was simple or compounded .in such cases ,we assume or take interest as simple otherwise it is incomplete question. basic formula used for amount in case of simple interest is P ( 1 + rt/100) .

explanation:

p (1 + 4r/100) = 620 --(1)

p(1+ 6r/100) = 680 ---(2)

devide eq.(2) by eq. (1)

(100 + 6r)/(100 + 4r) = 68/62

100r = 600 => r = 6%

from eq. (1)=> p ( 1+ 4×6/100) = 620

p = 62000/124 = Rs 500