John is saving at a faster rate than Barb.
John saves $35 the first week.
Barb saves $15 each week.
From the given graph, the rate of change of graph with points (0,15) and (5,90) will be
[tex]\text{Rate of change }==\frac{y_2-y_1}{x_2-x_1}=\frac{90-15}{5-0}=15[/tex]
Hence, the amount added to Barb's account each week=$15
From the given table, the rate of change of graph with points (1,35) and (3,75) will be
[tex]\text{Rate of change }=\frac{y_2-y_1}{x_2-x_1}=\frac{75-35}{3-1}=20[/tex]
Hence, the amount added to John's account each week=$20
Since, 20>15, thus John is saving at a faster rate than Barb.
The amount in Barb's account in the beginning=$15
From table, John saves $35 the first week.
The amount in John's account in the beginning=35-20=$15
Hence, they both have same amount in the beginning.