2 planes leave Houston..what time will they be 2100km apart?

[Algebra2Blues]

Help, please! I'm a Freshman in Algebra II and feeling so dumb after summer. I should know this. =o

Problem:
At 10:30 a.m. two planes leave Houston, one flying east at 560 km/h and the other flying west at 640 km/h. At what time will they be 2100 km apart?

I don't want the answer, just a boost in the right direction to get me started.

Thank you in advance. ^^

 

[Deleted member 4993]

Re: 2 planes leave Houston..what time will they be 2100km ap

Help, please! I'm a Freshman in Algebra II and feeling so dumb after summer. I should know this. =o

Problem:
At 10:30 a.m. two planes leave Houston, one flying east at 560 km/h and the other flying west at 640 km/h. At what time will they be 2100 km apart?

I don't want the answer, just a boost in the right direction to get me started.

Thank you in advance. ^^

How far apart are they - after flying for 1 hr.

 

[Algebra2Blues]

After one hour they should be 1200km apart.

 

[Deleted member 4993]

After one hour they should be 1200km apart.

so

to be 1200 km apart they must fly 60 minutes.

to be 1 km apart they must fly (60/1200 =) 0.05 minutes.

to be 2100 km apart they must fly ?? minutes

 

[Algebra2Blues]

They must be 105 minutes apart, 105minutes= 1 hr and 45 mins.

So it will be (10:30am + 1 hr 45) 12:15pm when they are 2100km apart.

Thank you so much. You're a star. (=

 

[Denis]

Mr/Miss Blues, easier to look at it this way:
2100 km to be covered at the comined speed of 1200 km/h; so:
2100 / 1200 = 1 3/4 or an hour and 45 minutes.

REMEMBER: time = distance / speed