mylne założenie

Doesn't that seem like a wrong assumption on their part?

Are you telling me that I made a wrong assumption somewhere along the line?

She didn't have to skim much to know she'd made a wrong assumption.

And if you make the wrong assumption, it's going to be worse.

I seem to be making any number of wrong assumptions these days.

Sometimes, even the wrong assumption that went with it helped.

I think, and collected most or all of my wrong assumptions about his work.

Each of the characters has made sensible but wrong assumptions about the other two.

"How far do you think your wrong assumption affected the calculations?"

They had all been making wrong assumptions about this case from the start.