A. Rs.2400/-
Feedback A's Share = Rs.10000/- per first 4 maonth + Next 8 months Rs.5000/- added
= 10 × 4 + 15 × 8 = 40 + 120 = 160
B's Share = Rs.20000/- per first 4 months + Next 8 months Rs.5000/- added
= 20 × 4 + 15 × 8 = 200
Then,A's part= 160 : B's part= 200
==> 4 : 5
Total 9 parts -----> Rs.5400/-
= 1 part ------> Rs.600/-
Then, A's share is
= 25parts = Rs.600/- × 4 parts = Rs.2400/-