A and B started a small business. B invested rs. 600 more than A. At the end of nine months from the start of the business, B doubles his investment. If at the end of the year the total profit earned was rs. 13800 and share of A in profit was 4800 rs. then find investment made by A

Let the investment made by A is, X. i.e
for 1month.so the investment for 12months is 12X.

And the investment made by B be,(X+600).i.e for 1month.so the investment for first 9months is 9(X+600), and the investment for next 3months is 3[2(X+600)].Then the overall investment made by B for 12months is, 15X+9000.

By this, we know that the ratio between A&B; is, 4X : (5X+3000).

Given that profit share of A is, 4800. i.e,
4X=4800
then X=1200
(or)
B's profit share = total share of profit _ A's profit share.
then, (5X+3000)=13800_4800
5X+3000=9000
5X=6000
so, X=1200.
Therefore, overall investment made by A is, 12X i.e, 12×1200= 14,400/-.

1200