Answer:

Let the B's income be 100

A's income = 100 + 30100×100=130\frac{30}{100} \times 100 = 130

100

30

×100=130

130 - 100 = 30

30130×100=30013\frac{30}{130} \times 100 = \frac{300}{13}

130

30

×100=

13

300

23113{ \color{lime}{23 \frac{1}{13}}}