Can a 10 inch tire fit on a 7 inch rim?

You must know the answer is NO.

Not necessarily true, we're talking about width I assume, the section width of the tire 10" in this case is measured at the widest part of the tire. The bead, the part of the tire that sits on the wheel, is significantly narrower. Just as an example P245/55R20, which is a 10" wide tire lists the apporved rim width as 7.0"-9.0", so depending on the exact size it is very possible that your 10" wide tire could go on a 7" wide rim.