Keegan makes a deposit into her savings account at the beginning of the year. The account earns 3% simple interest each year. Sh
e has $360.50 in her account at the end of the year. If Keegan did not make any additional deposits or withdrawals during the year, how much did she deposit into the account at the beginning of the year?
Let us assume that she deposited $P in the beginning. Now it says that account earns simple interest at a rate of 3%. And after 1 year the balance in account is $360.50. It means Amount ,A=$360.50 Rate ,r=3%=0.03 Time,t=1 year Principal =$P So Simple Interest earned in 1 year = Amount-principal We subtract principal from the amount So Simple Interest = A-P = 360.50 - P
Now we have a formula for Simple Interest SI =P*R*T
Lets plug the values 360.50-P = P *0.03*1 360.50-P = 0.03P Add P to both sides
360.50-P+P =0.03P+P 360.50 = 1.03P
Divide both sides by 1.03 350=P
So we get P=$350 So Principal =$350 In the beginning she deposited $350
