Question

At 10:00 a.m. two planes leave an airport. If the northbound plane flies at 280 mph and the southbound at 320 mph, at what time will they be 1,000 miles apart?

{ a.m.}

Answer 1

Distance = speed × time.

Answer 2

There are two distances and two speeds, but the two distances add up to 1000mi. and the time for both is the same.

Answer 3

how does 320+280=1000

Answer 4

320×time + 280×time = 1000.

Answer 5

You have to find the time.

Answer 6

"320+280=1000" would be 'speed + speed = distance' which doesn't make sense.

Answer 7

so speed + speed = distance means that it equals 600?

Answer 8

Speed + speed = distance is nonsensical and cannot be used.

There are two distances that add up to 1000, so you need distance1 + distance2 = total distance.
distance1=speed1×time, distance2=speed2×time.
The only unknown here is the amount of time.

Answer 9

so confusing

Answer 10

It does reduce to an equation that looks like a single speed of 600mph, and a single time of ? for a single total distance of 1000mi.

Answer 11

okay

Answer 12

Go back through everything I wrote a little at a time and think about it.
I'm sure you'll figure it out.

Answer 13

is the time 4:00 a.m.?