Answer:
bridget in week 13 will have 117 books and Cole in week 3 will also have 117 books 
Explanation:
find total books in a week 
Bridget =6+3=9
cole= 38+1=39
find lcm
9={3×3}
39={3×13}
lcm={3×3×13}
=117
for Bridget
117÷9 =13 weeks 
for cole
117÷39
3 weeks