The price elasticity of demand for plane rides is 05 The pri
     The price elasticity- of demand for plane rides is 0.5.  The price elasticity of demand for train rides is 0.2.  The cross elasticity of demand for train rides with respect to the price of a plane ride is 0.4.  If the price of a plane ride rises by 10 percent, the percentage change in the quantity demanded of plane ndcs is a decrease of  percent.  If the price of a plane ride rises by 10 percent, the percentage change in the quantity demanded of train rides is an increase of  percent. 
  
  Solution
1) Price elasticity for plane rides = % change in the quantity demanded for the plane rides / % change in the price of plane rides
0.5 = - % change in the quantity demanded for the plane rides / 10%
% change in the quantity demanded for the plane rides = 5% decline
2)
Cross Price elasticity for train rides = % change in the quantity demanded for the train rides / % change in the price of plane rides
0.4 = % change in the quantity demanded for the train rides / 10%
% change in the quantity demanded for the train rides = 4% increase

