3. Urn R contains n red balls and urn B contains n blue balls. At each stage a ball is selected at random from each urn and they are swapped. Show that the expected number of red balls in urn R after stage k is

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