Unable to solve this problem

Dear Student

Sales by Industry A to Industry B= Rs. 20 crore
Value added by Industry B= Rs.40 crore 
Sales by Industry B to Industry C= Rs. 20+40 Crore
                                                     = Rs.60 crore
Sales by Industry C to Industry D= Rs. 70 crore 
So value added by Industry C is = Rs.70 crore - Rs.60 crore
                                                     = Rs.10 crore 


Regards