Q:

a) i) Calculate the simple interest earned if a deposit of $ 900,000 is left for 12 years at an interest rate of 3% .ii) Calculate the interest rate for a 12 years investment of $600,000 to gained $180,000 interest.Solve the following pairs of simultaneous equations 3x + y = 7 and 2x - 2y = 2

Accepted Solution

A:
Answer:a)$ 324,000ii) 2.5%x=2, y=1Step-by-step explanation:(a)Simple interest is calculated by the formula[tex]I=Prt[/tex] I= Interest receivedP=Principalr= interest rate (per year)t=time (in years)I= ($900,000)(12)(3%)I=$324,000(ii)From the formula above, we find r[tex]I=Prt\\\\r=\frac{I}{Pt}\\ \\r=\frac{(180,000)}{(600,000)(12)}\\\\\\r=0.025\\\\[/tex]r=2.5%_______________________________3x+y=72x-2y=2Let's take 2x-2y=2we divide by 2 both sides and we getx-y = 1so x = 1+yand replace it in the other formula:3(1+y) + y = 73+3y+y = 73 + 4y = 74y = 7-34y= 4y = 1x = 1+yx = 1+1x = 2