Question

A sum of money becomes 3 times of itself is 4
years. In how much time it becomes 81 times of
itself?
a) 17 years.
c) 16 years
b) 19 years
d) 20 years​

Answer 1

Step-by-step explanation:

S = P x (1+I)^n

In first case S = 3 P = P x (1+I)^6

Or (1+I)^6 = 3

In second case

S = P x (1+I)^n

S = 81 P = P x (1+I)^n

81/3 = (1+I)^n / (1+I)^6

(1+I)^(n-6) = 27

n = 24

In 24 years, the sum at end will become 81 times the original sum.———————————————————

Let sum at start be 100

After 6 years it will become 100 x 3 = 300

After 12 years it will become 300 x 3 = 900

After 18 years it will become 900 x 3 = 2700

After 24 years it will become 2700 x 3 = 8100

Which is 81 times of initial amount of 100.

Earlier I had calculated with mathematical formulae

Answer 2

Answer:

Step-by-step explanation:

16 is the write answer