If a roof's slope is 0.5, how high will the roof rise over a 17-foot run?
a). 8 1/2 feet
b). 17feet
c). 1/34 feet
d). 34 feet

The answer to the mathematics question presented above would be letter a) 8 and 1/2 feet. If a roof's slope is 0.5, the height of the rise of the roof over a 17 foot run would be 8 and 1/2 feet. I got this answer through multiplying the slope and the run to get the rise. 

Answer a) 8 and half feet.

You calculate it in this way

slope = rise / run ⇒ rise = slope * run = 0.5 * 17 feet = 8.5 feet.

Maybe the answer is 20mm. all i really did was just multiply, which is obvious.