Answer:
50 years
Explanation:
use the simple interest formula :
PRT/100
P is the principle (5000)
R is the rate of interest (4)
T is the time taken (x- unknown)
the amount at the end is double the amount invested = 5000*2 = 10000
(5000*4 * x )/100 = 10000
20000x/100=10000
20000x = 100*10000
20000x = 1 000 000
x= 1 000 000/ 20 000
x = 50
it will take 50 years