ElectricPavlov

=  (1 x 3 x 4)  / ( 2 x 5 x 9)   = 12/90 = 2/15

Well.....if you combine the  11/16 and the 5/16  you will have 16/16   or a full case......and you still have the 7/16 left over...

Here is the website I used: 

https://www.mathsisfun.com/numbers/sigma-calculator.html

In reality, I THINK we may still not have QUITE the correct answer...I think the first year the payment is 2400 then the NEXT year it goes up 4 percent etc etc

so it would be

\( \sum_{0}^{39}\)2400(1.04)^n  = 228061.24       But that is not what I was asked.......

\(\sum_{1}^{40}\)2400(1.04)^n = 237183.69  sound about right?

Are you trying to calculate the value of a series of payments of 2400  over 40 periods with simple interest of 4% per period? ?

Not sure what that is in relation to, but that would be:

2400 x \(\sum_{1}^{40}\) n   *1.04 = 2400 (1.04)(820) = 2046720

WHO are you?  WHat do you need?  Did you submit a question?

Sometimes thee may not be anyone signed into the site that can answer your question and you will have a wait.....

= 9025  x  1728 =15595200

2400(1.04)^40 = 11522.45