1. **State the problem:** We need to find how many hours Salma and Mary each take to read a 120-page book. 2. **Find Salma's reading rate:** Salma reads 10 pages in 30 minutes, so her reading rate is $$\frac{10\text{ pages}}{30\text{ minutes}}=\frac{1}{3}\text{ pages per minute}.$$ 3. **Find time Salma needs for 120 pages:** Time = \(\frac{\text{total pages}}{\text{rate}}\), so $$\text{Time}_{Salma} = \frac{120}{\frac{1}{3}} = 120 \times 3 = 360 \text{ minutes}.$$ Convert to hours: $$\frac{360}{60} = 6 \text{ hours}.$$ 4. **Find Mary's reading rate:** Mary reads 5 pages in 20 minutes, so her reading rate is $$\frac{5\text{ pages}}{20\text{ minutes}} = \frac{1}{4} \text{ pages per minute}.$$ 5. **Find time Mary needs for 120 pages:** $$\text{Time}_{Mary} = \frac{120}{\frac{1}{4}} = 120 \times 4 = 480 \text{ minutes}.$$ Convert to hours: $$\frac{480}{60} = 8 \text{ hours}.$$ **Final answer:** - Salma needs 6 hours to read the 120-page book. - Mary needs 8 hours to read the 120-page book.