4. （3 points）A brother and sister go to buy stationery. The brother has twice as much money as the sister. The brother spends 180 yuan, and the sister spends 30 yuan. At this point, the money left with both of them is exactly equal. The brother brought $\qquad$ yuan, and the sister brought $\qquad$ yuan.
【Answer】Solution: According to the problem, we have:
The difference in their amounts of money is: $180-30=150$ (yuan);
According to the difference ratio formula, we get:
The amount of money the sister has is: $150 \div(2-1)=150$ (yuan);
The amount of money the brother has is: $150 \times 2=300$ (yuan).
Answer: The brother has 300 yuan, and the sister has 150 yuan.
Therefore, the answers are: 300,150.