Aman gave 30% of his monthly income to his father and of the remaining income, he gave 30% to his daughter and 25% to his wife. Aman invested the amount of money still remaining from his monthly income equally in three schemes. If he invested ₹42,000 in each scheme, what is Aman's monthly income (in ₹ thousand)?

Let's assume the monthly income of Aman is 100y.

Aman gave 30% of his monthly income to his father and of the remaining income, he gave 30% to his daughter and 25% to his wife.

Remaining money (after giving money to his father, daughter, and wife) = 100y of (100-30)% of (100-30-25)%

= 100y of 70% of 45%

= 31.5y

Aman invested the amount of money still remaining from his monthly income equally in three schemes.

So Investment in each scheme = $$\frac{31.5y}{3}\ =\ 10.5y$$ 

If he invested ₹42,000 in each scheme.

10.5y = 42000

y = 4000

100y = 400000

Aman's monthly income (in ₹ thousand) = 400 thousand