Answer:
9.61
Step-by-step explanation:
Let the certain sum of money be A and x be the time in which A will be 2.5 times,
A[tex](1+0.1)^{x}[/tex] = 2.5A
[tex](1.1)^{x}[/tex] = 2.5
using log(x) both sides,
log[tex](1.1)^{x}[/tex] = log(2.5)
xlog(1.1) = log(2.5)
x = [tex]\frac{log(2.5)}{log(1.1)}[/tex]
x = 9.61
