Dear student
The reduction reaction is:
CuO+C Cu+CO
1mole of C gives 1 mole of Cu
1mole of Cu is obtained from 1 mole of C
63g of Cu is obtained from 12g C
1g will be obtained from 63/12 g C
1.6 x 107 g will be obtained from 63/12 x 1.6 x 107 g
= 8.4 x 107 g
Regards