Given:
Rate of simple interest = 5%
Time = 4 years
Total interest = $160
To find:
The amount borrowed by Austin from a credit union.
Solution:
The formula for simple interest is:
[tex]I=\dfrac{P\times r\times t}{100}[/tex]
Where, P is principal, r is the rate of interest and t is the number of years.
Putting [tex]I=160,r=5,t=4[/tex] in the above formula, we get
[tex]160=\dfrac{P\times 5\times 4}{100}[/tex]
[tex]160=\dfrac{20P}{100}[/tex]
[tex]160=\dfrac{P}{5}[/tex]
Multiply both sides by 5.
[tex]800=P[/tex]
Therefore, Austin borrowed $800 from a credit union for 4 years.