Explain question no 16 briefly under 30 mins

Dear Student
Old Ratio- 5:3:2
Q's share = 3/10
P's New share = 5/10 + (3/10*2/3) = 5/10 + 2/10 = 7/10
R​​​​​'s New share = 2/10 + (3/10*1/3) = 2/10 + 1/10 = 3/10
New Ratio = 7:3
Answer is b) 7:3

Regards