You need to find out how much is 80% of 10.
80% = 80/100 = 8/10 = 4/5.
so what is (4/5)(10/32)?
one you have that, say as a/b, you need to express this in 32nds.
if (by luck) there is a number c such that bc = 32, then a/b = ac/32. the "legal limit" of remaining tread is then (10 - ac)/32.
Which question are you referring to?
8/32 = 1/4.
Shouldn't the question be: how do you express 1/16 as 32nds, since 2/32 = 1/16?
2/32 is the answer to both questions btw.
80% of equals
This can be calculated:
Your question states: If 80% of the tread has worn off.
That means that we subtract 80% from the original number:
inches
As for the second part of your problem. It asks:
How much tread wear remains if the tread depth is ?
We now consider that the legal minimum for tread is
That means that we have to find the difference between the two:
inches of tread remaining.