A paint-store chain produces and sells semigloss paint and rollers. Based on long-range sales, the probability that a customer will purchase semigloss paint is 0.75. Of those that purchase semigloss paint, 15% also purchase rollers. It is also known that 20% customers purchase rollers. Given that a customer did not purchase a roller, what is the probability that he/she will also not purchase semigloss paint