Answer:
statement A, C, D, are true.
Step-by-step explanation:
We check all the statements by the rule of 72 to find which statement about doubling an investment are true.
Formula we use = [tex]\frac{72}{R}[/tex] R = Rate of interest
Statement A :
An investment of $5,000 will double in 6 years at an annual compound interest rate of 12%.
[tex]\frac{72}{12}[/tex] = 6 years
It will take 6 years to double the investment. This statement is true.
Statement B :
An investment of $1000 will double at an annual compound interest rate of 18% in 6 years.
[tex]\frac{72}{18}[/tex] = 4 years
It will take 4 years to double the investment. This statement is not true.
Statement C:
An investment of $350 will double in 9 years at a compound interest rate of 8%.
[tex]\frac{72}{8}[/tex] = 9 years
It will take 9 years to double the investment. This statement is true.
Statement D :
An investment of $2000 will double at a simple interest rate of 5% in 20 years.
Formula for Simple interest = (PRT)
I = (2000 × 0.05 × 20) = $2000
So the amount will be 4000 in 20 years. This statement is true.
Statement E :
An investment of $700 will double in 12 years at a simple interest rate of 6%
Interest = ( 700 × 0.06 × 12 ) = $504
Amount after 12 years 700 + 504 = $1204. This statement is not true.
