How many 6by6 inch tiles needed to cover 925 sq inches?

Answer 1

Area of each tile = 6*6 = 36 sq inches.

So number of tiles required = round-up(925/6) = 155.

This, however, is the minimum number of tiles required and is based on the assumptions that the area is well behaved and that offcuts are mostly used. In real life, you should allow at least 5% for breakage and waste.