ใครเก่งเศรษฐศาสตร์ช่วยอธิบายข้อนี้ให้คะ

Economists have estimated the following transportation elastics .For each pair,explian possible reason why the elasticities differ.

a.Elasticity of demand for buses is 0.23 during peak hour and 0.42 during off-peak hours.

b.Elasticity of demand of buses is 0.7 in the short run and 1.5 in the long run.

c.Elasticity of demand for toll road 4.7 for low-income commuters and 0.63 high-income commuters.