Create a multiplication formula which adds an amount each time

[Jembop]

I need to multiple a value call it x by an amount, but each time the amount increases by 500k. I can't simply say =(x * amount) I need to do x * amount and amount + 500000 * x but whatever I try it's not the correct number so can someone help me with the syntax?

 

[RobP]

Hi would this help you ? (if I understand your question well) ?

Book1
	A	B	C	D
1	1500	500000	750000000
2
Sheet1

Cell Formulas
Range	Formula
C1	C1	=IF(MOD(B1,500000)=0,A1*B1,A1)

 

[RobP]

So 1500 in A1 would be multiplied by B1 only if B1 was 500,000 or 1,000,000 or 1,500000 for example ? otherwise it would be left as A1

 

[Jembop]

Thanks for getting back to me @RobP

Not quite - here's an example of what I'm trying to get at. I have a cost at 110.5 million, and 300 iterations left to multiply that to.
However each iteration goes up by 500k. So iteration 300 will cost 110.5m but iteration 301 will cost 111m and so on.
As you can see when I multiply the cost and the multiplier both by 300 separately and add them together (cell F2) I get 33.3bn.

However I manually counted 1 to 300 in cells C4 to C303 and added the 500k multiplier to each row and summed that, and I get 55,575,000,000 which is 22bn more.

So what I want cell F2 to do is calculate correctly multiplying D2 by C2 but adding E2 each time to D2. Make sense?!?

 

[Fluff]

How about

=SUM(SEQUENCE(C2,,D2,E2))

 

[RobP]

sorry, having a hard time understanding the question - but are you basically saying you want to add the multiplier (E2) to the current cost (D2) 300 times (C2) ?

+c2*e2+d2

So the answer is 260500000 ?

Please let us know what your expected result would be in F2 if thats not the case ?
thanks
Rob

 

[Jembop]

How about

=SUM(SEQUENCE(C2,,D2,E2))

Thank you this worked perfectly!

 

[Fluff]

Glad we could help & thanks for the feedback.

 

[RobP]

indeed.. thanks - I read
"However I manually counted 1 to 300 in cells C4 to C303 and added the 500k multiplier to each row and summed that, and I get 55,575,000,000 which is 22bn more."

and assumed therefore that was the incorrect answer ....

apologies