Three years ago, the sum of the ages of the father and son was 48 years. After three years the ratio of the ages of the father and son will be 3:1,then how much old the father than his son?

Two trains leave a station on different tracks. the tracks make an angle of 130°, with the station as a vertex. the first train travels 100 km and makes its first stop at point a, while the second train travels 200 km and makes it first stop at point b. how far apart are the trains when both are at their first stop? round the answer to the nearest integer. a) 65 km b) 139 km c) 224 km d) 275 km