I need an explanation on how to solve these problems ​

Planning for the possibility that your home might get struck by lighting and catch on fire is part of a plan

Aplane is taking off from bangladesh headed to new york city. at the same time, a plane from new york city is headed to bangladesh is also taking off. the plane bound to new york city is traveling at 600 mph, while the plane traveling to bangladesh is traveling at 400 mph. how far from new york city will the two planes meet if the distance between new york city and bangladesh is 8,000 miles?

Jack did 3/5 of all problems on his weekend homework before sunday. on sunday he solved 1/3 of what was left and the last 4 problems. how many problems were assigned for the weekend?