About how long does it take an elevator to go from the ground floor to the observation deck at a height of 869 ft?

The product of two negative rational numbers is always zero sometimes zero never zero

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?

What is the range? can’t seem to find it out