Answer: 6.93 years
Step-by-step explanation:
Given
Rate of interest is 
Future value is given by 
For the investment to double itself, i.e. 

It takes around 6.93 years to double the investment.
Answer:
Step-by-step explanation:
the formula for circumference of a circle is 2 x pi x r(radius).
(-2,0) (0,6) (1,0) this should be it
Answer:
x = 20
Step-by-step explanation:
x/10 = 2 multiply both sides of the equation by ten ↓
10x x/10 = 10 x 2 reduce the numbers with the greatest common factor 10 ↓
x = 10 x 2 multiply the numbers ↓
x = 20