(i) It is given that
Ratio between A,B and C = 7:5:4
Consider,
A share = 7x
B share = 5x
C share = 4x
So the total sum =7x+5x+4x=16x
Based on the condition
5x–4x=500
x=500
So the total sum =16x=16×500=Rs 8000
(ii) 1 months investment of A=Rs 50000
6 month investment of A=50000×6=Rs 300000
1 months investment of B=Rs 60000
4 month investment of B=60000×4=Rs 240000
1 months investment of C=Rs 80000
5 month investment of C=80000×5=Rs 400000
Here the ratio between their investments = 300000:240000:400000=30:24:40
Sum of ratio = 30=24+40=94
Total earnings = Rs 18800
So we get share of earning by each as ,
A share = 3094×18800=Rs 6000
B share = 2494×18800=Rs 4800
C share = 4094×18800=Rs 8000