The formula is:
[tex]A=P(1+ \frac{r}{n} ) ^{(n)(t)} [/tex]
where:
A = amount accumulated; Php 5,000
P - principal/amount inversted; unknown
r = interest rate (compounded) at 4% or 0.04
n = compounding per period; semi-annually; 2
t = number of periods, 8 years
nt = (2) (8) = 16
Equation:
[tex]5,000 = P (1 + \frac{0.04}{2} ) ^{16} [/tex]
[tex]5,000 = P (1.02) ^{16} [/tex]
[tex]5000 = P (1.373)[/tex]
[tex]P = \frac{5,000}{1.373} [/tex]
P = 3,641.66 or 3,642.00
The amount invested is Php 3,642.00