The average weight of 49 students is 53 kg. When a new student is admitted to the class, the average decreases by 500 g. Find the weight of the new student.

The class originally has $$49$$ students, each with an average weight of $$53 \text{ kg}$$.

Total weight of the original students $$= 49 \times 53 = 2597 \text{ kg}$$.

After admitting one more student, the class strength becomes $$50$$ and the average weight falls by $$0.5 \text{ kg}$$ (since $$500 \text{ g} = 0.5 \text{ kg}$$).

New average weight $$= 53 - 0.5 = 52.5 \text{ kg}$$.

New total weight $$= 50 \times 52.5 = 2625 \text{ kg}$$.

Weight of the new student $$= 2625 - 2597 = 28 \text{ kg}$$.

Therefore, the new student weighs $$28 \text{ kg}$$.

Option C which is: 28 kg