Can anyone please help me out with this problem?

Question

Mr. Brown leaves 2.5 hours before Mrs. Brown. If he averages 60 MPH and she averages 90 MPH, how long will it take Mrs. Brown to overtake Mrs. Brown?

Answer 1

Since Mrs. Brown is going 30 mph faster then Mr. Brown, solve the equation 30t=150 t=5 hours.

Answer 2

Let t be the time needed.

Mr. Brown has travelled for t+2.5 hrs when the overtaking happens and Mrs. Brown has travelled t hrs. The distance travelled is the same for both = Speed X Time

Solve, 60 (t+2.5) = 90(t)
to get t = 5 hrs

Answer 3

All you have to do is multiply 2.5hrs X 60mph = 150miles/90mph= 1.67 (the1 in 1.67 is an hour, but to get the mins and secs you have to multiply .67 X 60= 40.2 or 40 mins 20 secs) then multiply 1.67X60=(answer)/90=(time she drove)X60=(answer)/90=more time she drove. At the end stop the equation once u get an answer of 0 or close to 0 and add all the time she drove which should be around 5 hours 2 mins 36 seconds.

but this is the long way

Wow....I wish you could see the paper i was writting on.lol

Answer 4

let x be the time Mr.B leaves
x-2.5 is the time Mrs.B leaves

when Mrs. Brown catches him, their distances will be the same
x = vt(Mr.B)
x = vt(Mrs.B)

vt(Mr.B) = vt (Mrs.B)
60x = 90(x-2.5)
60x = 90x - 225
-30x = -225
x = 7.5hr

it will take her 7.5 - 2.5 = 5hrs to catch him

Hope this helps.