The demand for bus rides per month is estimated to follow the equation:

Q = 9,750 - 500p + 5i + 250Pt

wherepis the price of a bus ride, i is the average consumer income, andPtis the price of a train ride.

Suppose thatp = 1.50,Pt= $400 andi = $3000. What is the cross-price elasticity of demand? Are bus and train rides substitutes or complements?

As in (a), suppose that p = 1.50,Pt= $400 andi = $3000. What is the own price elasticity of demand for bus rides?

Suppose that the price of a train ride falls to Pt =$350. What should be the change in the price of bus rides to guarantee that the demand for bus rides does not change?