A man sells Rs.5000, 12 % stock at 156 and uinvests the proceeds parity in 8 % stock at 90 and 9 % stock at 108. He hereby increases his income by Rs. 70. How much of the proceeds were invested in each stock?

A. 3600(8%), 4200(9%)
B. 4000(8%), 4200(9%)
C. 3600(8%), 4000(9%)
D. 4000(8%), 4000(9%)
S.P of Rs. 5000 stock = Rs. [(156/100)*5000] = Rs. 7800.
Income from this stock = Rs. [(12/100)*5000] = Rs. 600.
Let investment in * % stock be x and that in 9 % stock = (7800-x).
[x*(8/90)] + (7800-x) * (9/108) = (600+7)
4x/45) + [(7800-x)/12] = 670  16x + 117000-15x = (670*180)
x = 3600
Money invested in 8 % stock at 90 = Rs. 3600.
Money invested in 9 % at 108 = Rs. (7800-3600) = Rs. 4200.