Saving for education

Suppose a couple invested ₱50,000 in an account when their child was born, to save for college. The average annual interest rate is 4.4%, compounded annually.

a) Give an exponential model for the situation.
b) Will the money have doubled by the time the child turns 18 years old?

Result

x=

Yes

No

Step-by-step explanation:

$$\begin{gathered} x_0=50000\text{Php} \\ q=100\%+4.4\%=1+\frac{4.4}{100}=1.044 \\ t=18\text{y} \\ k=q^{18}=1.044^{18}\doteq 2.1707 \\ {x}_{18}=x_0\cdot k=50000\cdot 2.1707\doteq 108537.2916\text{Php} \\ k>2 \\ x=1 \end{gathered}$$

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