Answer:
The key to this question is converting all the mass units to the same unit and adding them all up.
The only value that isn't consistent with the other units is 450 gm or grams.
Recall that 1 gram is equal to 0.001 kilo grams. So if you want to convert grams to kilograms you would multiply that amount by 0.001 or 1/1000
Now let's add up all the masses.
(Now a few footnotes here, that I considered but wasn't sure about. The answer asks for weight, but you're only given mass to work with. That would be fine, if the question asked you to convert it to SI weight units like Newtons, but there's no mention of that. And also I'm not sure if the question requires significant digits. But I'll continue the answer if you think so)
To convert this into weight in Newtons, multiply by 9.81 m/s^2