A radio station has a promotion in which it announces that a local petrol station will sell petrol

at 95 cents per litre beginning in 30 minutes. Jack hops in his car and drives to the station to fill

up his half-empty tank. He pays only $19 for 20 litres instead of the going price of $29.

-

Did Jack save $10.00? Is the radio station doing its listeners a favour by offering this

promotion? Briefly explain.