Explanation:
wow, how complicated can one phrase this ...
the point being :
1 ft = 12 in and vice versa (1 in = 1/12 ft)
so, any measurements given in feet but needed in inches need to be multiplied by 12.
and any measurements given in inches but needed in feet need to be divided by 12.
so,
3.5 ft = 3.5×12 = 7/2 × 12 = 7×6 = 42 in
27 in = 27/12 = 9/4 = 2 1/4 or 2.25 ft