This shows that Billy will have $12, 168.25 after 12 years
<h3>Compound interest</h3>
The formula for calculating the compound interest is expressed as:
From the information given, the amount is expressed as;

This shows that Billy will have $12, 168.25 after 12 years
Learn more on compound interest here: brainly.com/question/24924853
5^-3=0.008
1/2=0.5
0.5*0.008=0.004
5/0.004=1250
7 1 8 You can also calculate this using the Fundemental Counting Principle, just do 3*2*1 which is 6 passwords
7 8 1
8 1 7
8 7 1
1 7 8
1 8 7
200*50=10,000.
2*5=10
20*50=1000
200*50=10000