Question

Ci for first year is 2592 and third year ci is 3528 find ci for
4th year
​

Answer 1

Given: The CI for 1st year is Rs. 2592 and that for 3rd year is Rs. 3528.

To find: CI of 4 th year?

Solution:

• Now the formula of CI is:

                   CI = P ( (1+(R/100))^T )

                   P = principal, R = rate and T is time period.

• Now: according to the question, we have:

                   P(1+R/100) - P = 2592

                   P(1+R/100)³ - P(1+R/100)² = 3528

• From this, we get:

                   PR = 259200   ....................(i)

                   PR(1+R/100)(1+R/100) = 352800.     ....................(ii)

• Putting (i) in (ii), we get:

                   259200(1+R/100)(1+R/100) = 352800

                   (1+R/100)² = 352800/ 259200

                   (1+R/100)² = 3528/2592

                   (1+R/100)² = 49/36

                   (1+R/100)² = (7/6)²

• Taking square root on both sides, we get:

                   1+R/100 = 7/6

                   R/100 = 7/6 - 1

                   R/100 = 1/6

                   R = 100/6

                   R = 50/3

• Putting R in (i), we get:

                   P(50/3) = 259200

                   P = 15552

• So the CI for 4th year can be calculated by :

                   P(1+R/100)(1+R/100)(1+R/100)(R/100).

• After putting values and solving it, we get:

                   (1 + 100/6(100) )^3 x 1/6 x 15552

                   Rs. 4116

Answer:

           So the CI of 4 th year is Rs. 4116.