7.4. What angle do the hour and minute hands form at twenty minutes past one? (Don't forget to justify your answer).
7.4 $110^{\circ}$.

At 12:00, the angle between the hour and minute hands is $0^{\circ}$. The minute hand completes a full circle of $360^{\circ}$ in 60 minutes, which is $6^{\circ}$ per minute, and in 20 minutes it will cover $120^{\circ}$. The hour hand moves 12 times slower than the minute hand. Therefore, in 20 minutes, it will cover an angle of $10^{\circ}$. Thus, in 20 minutes, the angle between the hour and minute hands will be $110^{\circ}$.