Calculating the Period of an Investment (Grade 12 NSC Matric Mathematics): Flashcards

Finding how long money must be invested to reach target amount

$A = P(1 + i)^n$

Accumulated amount (final value)

Principal amount (initial investment)

Interest rate as a decimal

Time period

$n = \frac{\log(A/P)}{\log(1 + i)}$

Round up to next whole number

Forgetting to convert to decimal (divide by 100)

Divide both sides by $P$: $\frac{A}{P} = (1 + i)^n$