Answer:
Option C
Explanation:
The number of non-academic books published by publishers R and S.
= $\frac{6}{17}\times35700 + \frac{13}{18}\times37800$
= 12600 + 27300 = 39900
The average number of non-academic books published by Publishers R and S
= $\frac{39900}{2}$ = 19950
