Question

A savings account compounds interest, at a rate of 22%, once a year. George puts $750 in the account as the principal. How can George set up a function to track the amount of money he has?
a. A(x) = 750(1 + .22)x where .22 is the interest rate
b. A(x) = 750(22)x where 22 is the interest rate
c. A(x) = 750(.22)x where .22 is the interest rate
d. A(x) = 750(1 + 22)x where 22 is the interest rate

Answer 1

George shouldn't think too far.

He should use the formula for Compound Interest.

Amount in compound interest, A = P(1+ r/100)ⁿ.

Where A = Amount, P = Principal, r is the rate per year, n = number of years.

Note: the expression (1+ r/100) is raised to power  n.     

From George's problem: P = 750,    r = 22,  I guess number of years , n = x

A(x) = 750( 1 + 22/100)ˣ

A(x) = 750( 1 + 0.22)ˣ 

From your options I can't see an answer. Except the expression of option (A) is actually raised to power x, and not times x as stated in the option.