Printing Cost of book = 20% of C.P.
Royalty on book = 15% of C.P
Difference = (20% of C.P) – (15% of C.P) = 5% of C.P.
⸫ Percentage difference =
=  = 25% = 25%
Thus, Royalty on the book is 25% less than the printing Cost. 

Let the Promotion cost for this edition be Rs. p.
Then, 25 : 10 = 56250 : p ⇒ p = Rs.  = Rs. 22500.

Central angle of 108⁰ =  of the total expenditure= 30% of the total expenditure.
From the pie – chart it is clear that:
Binding Cost + Transportation Cost = (20% + 10%) of the total expenditure
= 30% of the total expenditure
⸫ Binding Cost and Transportation Cost together have a central angle of 108⁰. 

Clearly, S.P. of the book = 105% of C.P.
Let the selling price of this edition (of 12500 books) be Rs. x.
Then, 15 : 105 = 281250 : x ⇒ x = Rs.  = Rs. 1968750.
⸫ S.P of one book = Rs.  = Rs. 157.50

Central angle corresponding to Royalty = (15% of 360)°= 54° 

Clearly, marked price of the book = 120% of C.P
Also, cost of paper = 25% of C.P.
Let the cost of paper for a single book be Rs. n.
Then, 120 : 25 = 180 : n ⇒ n = Rs.  = Rs. 37.50

Let the amount of Royalty to be paid for these books be Rs. p.

Then, 20 : 15 = 30600 : r ⇒ r = Rs. = Rs. 22950.