Doing the inverse of a calculation

For me to know how much I need to invest knowing how much I want in return, I do it this way:

Return expected → D2: 7.32
Market odds → C2: 1.41

Amount to invest → E2:

=(C2-1)*D2

Rounded result:

3.00  

But what if I know how much I want to invest(3.00), how do I reverse this calculation?

Amount to invest → E2: 3.00
Market odds → C2: 1.41
Return expected→ D2: ???

Additional information for users to gambling tag:

I’m looking to invest in Lay on the Exchange market.

>Solution :

If E2 = (C2-1)*D2, then

• E2/D2 = (C2-1)
• D2/E2 = 1/(C2-1)
• D2 = E2/(C2-1)

So, according to your data:

• Amount to invest → E2: 3.00
• Market odds → C2: 1.41

You can compute Return expected as:

D2 = 3/(1.41-1) = ~7.317