George saves 18% of his total gross weekly earnings from his 2 part-time jobs. He earns $6.25 per hour from one part-time job and $7.50 per hour from the other part-time job. George works a total of 40 hours between the two jobs each week?

George saves 18% of his total gross weekly earnings from his 2 part-time jobs. He earns $6.25 per hour from one part-time job and $7.50 per hour from the other part-time job. George works a total of 40 hours between the two jobs each week. What additional information is needed to determine the amount of his earnings he saves each week?