Answer:
Option D
Explanation:
Total investment = Rs. $\left(120\times 80+280+\frac{40}{100}\times 120+72\right)$
= Rs. $(9600+280+48+72)$
= Rs. $10000$
S.P of 120 reams $=108$% of Rs. $10000$.
= Rs. $10800$
$\therefore$ S.P per ream = Rs. $\left(\frac{10800}{120}\right)$
= Rs. 90.