The speed of losing weight varies from person to person and depends on many factors, including basal metabolic rate, diet, exercise, lifestyle and health status. Generally speaking, a healthy weight loss rate is 0.5 kg to 1 kg per week.

According to the information you provided, going to the gym three or four times a week, doing aerobic exercise for one and a half hours each time, and skipping dinner, these measures are helpful to lose weight. However, the specific weight loss rate also depends on factors such as your diet intake and physical condition.

If you want to lose weight 10 kg, it usually takes at least 3 to 6 months, but the specific time still varies from person to person. It is important to be patient and persistent, while paying attention to a reasonable diet and proper exercise. It is recommended that you pay close attention to your physical condition during weight loss, and consult a doctor or dietitian for any discomfort.