Please help me in this

Qs.4. The following table gives some data on the supply of long-distance phone calls: Price Qs in the Short-Run Qs in the Long-Run (cents/minute) (millions of minutes/day) (millions of minutes/day) 10 300 0 20 500 500 30 700 1000 At 20 cents a minute, calculate the elasticity of: a) Short-run supply b) Long-run supply