Across-country skier covered 1/3 of her race in one hour, 2/5 of the race during the next hour, and the remainder of her race in the third hour. what fraction of the race did the skier cover during her third hour?

The figure shows triangle def and line segment bc, which is parallel to ef: triangle def has a point b on side de and point c on side df. the line bc is parallel to the line ef. part a: is triangle def similar to triangle dbc? explain using what you know about triangle similarity. part b: which line segment on triangle dbc corresponds to line segment ef? explain your answer. part c: which angle on triangle dbc corresponds to angle f? explain your answer. asap