We know that
1 foot = 12 inches
Therefore,
[tex]1\text{ inch = }\frac{1\text{foot}}{12\text{ inches}}\text{ }[/tex]Here, we are told to convert 100 inches per minute to feet per minute.
To convert 100 inches per minute to feet per minute, multiply by 1 foot/12 inches.
Thus, we have:
[tex]\frac{100inches}{1min\text{ute}}\text{ }\ast\text{ }\frac{1\text{foot}}{12\text{inches}}[/tex]