Caroline can sketch 8 cartoon strips in five hours. How long will it take her to sketch 24

cartoon strips?

If Caroline can sketch 8 cartoon strips in 5 hours, then she can sketch 1 cartoon strip in 5/8 = <<5/8=0.625>>0.625 hours.
Therefore, it will take her 0.625 x 24 = <<0.625*24=15>>15 hours to sketch 24 cartoon strips. Answer: \boxed{15}.