A person invest $8800 in an account at 7% interest compounded annually. When will the value of the investment be 13,200? (Type an integer or decimal rounded two decimal places as needed)

21.43

Step-by-step explanation:

Turn 7 percent to a decimal: 0.07

8800 × 0.07 = 616

13,200÷616=21.4285 etc

Round two decimal places

21.43

answer is b

step-by-step explanation:

let x and 400 - x be the two numbers.  

==> 0.80x + 0.85(400 - x) = 400 - 68 from the statement of the problem.  

< ==> 0.80x + 0.85(400 - x) = 400 - 68  

==> 340 - 0.05x = 332  

< ==> -0.05x = -8 ==> x = 160, the first number ==> 400 - x = 240, the second number.