doubt for word problem expert

Question

Mr jones gave 40% of the money he had to his wife. he also gave 20% of the remaining amt to each of his three sons. half of the amt now left was spent on miscellaneous items and remaining amt of Rs 12000 was deposited in the bank how much money did mr jones have initially

i know full solution answer dont try to explain me

in math language "of" means *, here in some situation we do according to problem like below two examples but third one doest follow question i want to know that when we should go as per the question and when we shouldt go



i assumed that he had x money

40% of the money
40/100*x which is 2x/5 ------ wife

20% of the remaining amt
20%100*3x/5
(3x/5)3------------sons amt get 9x/5

remaining amt of Rs 12000
i know remaining amt is 3x/25
as per question stated it should be like this 3x/25*12000 it is wrong
but right is 3x/25=12000
please explain me definite solution 

Answer 1

40% to wife

20% of 60%= 12% to 3 sons, or 4% to each son

leaving 100-40-12 = 58%

58% of 100= 58