Pierre is running 26 and 2/10 miles in a marathon. he has run 3/4 of the way. how far had he run?

Distance=(3/4) * (26  2/10  miles)

26  2/10  miles=26  1/5 miles=(5*26+1) / 5 miles=131/5 miles.

Therefore:

distance=(3/4) * (26  2/10 miles)=(3/4) * (131 /5 miles)=
=(131 *3) / (4*5) miles=393/20 miles= (19*20+13)20 miles=19  13/20 miles.

he has run 393/20 miles    or    19  13/20  miles

Convert all into miles.

26 miles + 2/10 mile
(26 * 10/10) + 2/10 #remember, 10/10=1 and multiplying anything by 1 is itself!
260/10 miles + 2/10 mile
Now the denominator is the same so you can just add the numerator

260+2 =262
The total miles!

Now 3/4 of it:
Multiply the total miles by 3/4
262 * (3/4)

262 * 3 = 786
786/4 = 196 and 1/2 mile.

That's the distance he has already completed