George saves 18% of his total gross weekly earnings from his 2 part-time jobs here in $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 two jobs each week what additional information needed to determine the amount of the earnings he saves each week

His total earnings would be (18%)[$6.25(hours in 1st job) + $7.50(hours in 2nd job)]. However, we know that his total hours is 40 hours, so if we let the number of hours he spends in his 1st job be x, the number of hours in the 2nd is (40 - x).
Then his total earnings would be. This means that we need to know the time he spends in 1 job (either the first or the second will do).