It is a 3 km hike to the river pj walks for 500 m then he walks another 1050 m how
many more kilometers must pj hike to the reach the river

He must walk 1.45 more kilometers.
1050 meters and 500 meters add are 1550 meters.
1550 meters then convert to 1.55 kilometers.
You subtract 1.55 from 3 and get 1.45 kilometers.