Question

Speed distance time problem?

Answer 1

800 miles

Explanation:

As they head together the gap between reduces.

Numerically you will get the same answer if you add their speeds and treat the condition as if you have one plane heading towards a fixed point.

Let the distance to the destination be `d` in miles
Let the velocity be `v` in miles per hour
Let the time be `t` in hours

Using the principle that the velocity is constant then there is a direct comparison between the distance travelled in `1/4` an hour to that travelled in 1 hour

Using ratio but in the format of a fraction

`("distance")/("time")=d/t=200/(1/4)=d/1`

so `d=200-:1/4 color(white)("ddd")=color(white)("ddd") 200xx4/1 color(white)("ddd")=color(white)("ddd") 800" miles"`