**Calculating the Weight of a Single Box**

To calculate the weight of a single box, we need to convert the weight from kilograms and grams to a single unit. In this case, we will convert everything to grams for simplicity.

Given that the weight of the box is 4 kg 800 gm, we can convert this to grams as follows:

1 kg = 1000 gm
4 kg = 4 * 1000 gm = 4000 gm
800 gm = 800 gm

Therefore, the weight of a single box is 4000 gm + 800 gm = 4800 gm.

**Calculating the Total Weight of 150 Boxes**

To calculate the total weight of 150 boxes, we need to multiply the weight of a single box by the total number of boxes.

Weight of a single box = 4800 gm
Total number of boxes = 150

To find the total weight, we multiply the weight of a single box by the total number of boxes:

Total weight = 4800 gm * 150 = 720,000 gm

**Converting the Total Weight to Kilograms**

The total weight we obtained is in grams. To convert it to kilograms, we divide the total weight by 1000.

Total weight in kilograms = 720,000 gm / 1000 = 720 kg

Therefore, the total weight of 150 boxes is 720 kg.

**Summary:**

- The weight of a single box is 4 kg 800 gm, which is equivalent to 4800 gm.
- To find the total weight of 150 boxes, we multiply the weight of a single box (4800 gm) by the total number of boxes (150).
- The total weight of 150 boxes is 720,000 gm.
- Finally, we convert the total weight from grams to kilograms by dividing it by 1000, giving us a total weight of 720 kg.