The average height of 12 students of a class is 132.5 cm. Ifone more strident joins. the average height becomes 131.2 cm. the height of the new student is:

The average height of the first $$12$$ students is given as $$132.5 \text{ cm}$$.

Average $$=\frac{\text{Total height}}{\text{Number of students}}$$, so the total height of these $$12$$ students is
$$\text{Total}_{12}=12 \times 132.5 = 1590 \text{ cm}$$.

After one more student joins, the class strength becomes $$13$$ and the average height becomes $$131.2 \text{ cm}$$. Therefore the new total height is
$$\text{Total}_{13}=13 \times 131.2 = 1705.6 \text{ cm}$$.

The height of the new student is the difference between the two totals:
$$h_{\text{new}} = \text{Total}_{13} - \text{Total}_{12} = 1705.6 - 1590 = 115.6 \text{ cm}$$.

Hence, the height of the new student is $$115.6 \text{ cm}$$.

Option C which is: 115.6 cm