When signing the lease for her new apartment, tanya paid a security deposit that earned 4% simple annual interest. at the end of a year, the interest earned on the security deposit was $17.50. how much was the security deposit?

The simple interest formula is
I=prt
Where
I the interest earned 17.5
P security deposit ?
R interest rate 4%=0.04
T time 1 year
17.5=p×0.04×1
Solve for p
17.5=0.04p
Divide both sides by 0.04 to get
P=17.5÷0.04
p=437.5 is the amount of security deposit.

Hope it helps!