Should be 660 yards.
Since one mile is 1760 yards, trail A is 1760 yards. To find trail B we suubtract 200 from 1760 giving us 1560.
Now we know that trail B is 1560.
To find out trail C we subtract 900 yards from 1560 giving us 660.
Trail C is 660 yards. Hopefully u get it correct.
