To convert the length of the whiteboard from feet to inches, you can use the conversion ratio where 1 foot equals 12 inches.
The whiteboard is 7.5 feet long.
To find the length in inches: \[ 7.5 \text{ feet} \times 12 \text{ inches/foot} = 90 \text{ inches} \]
So, the whiteboard is 90 inches long.
The correct response is 90.