Math Question First Correct Gets Best Answer?

Question

A train traveling at a speed of 30 miles per hour passes point A on its way to point B. At the same time on a parallel track another train traveling at a speed of 70 miles per hour passes point B on it's way to point A. If point A and point B are 300 miles apart how far from point B will the trains meet?

F_240 miles

G_210 miles

H_150 miles

J_140 miles

K_90 miles

Answer 1

210 miles

30mph * 3 hrs is 90 miles from point A and 210 miles from point B

70mph * 3 hrs is 210 miles from point B and 90 miles from point A

Answer 2

k 90 miles

Answer 3

2

Answer 4

K-90 miles

Answer 5

k 90 miles  

Answer 6

g 210 from b

Answer 7

Looks like it's either 210 or 90.  210 is correct.  Draw a number line and look at Philbert's explanation.

Answer 8

G_210 miles

Answer 9

30:70 means 7/10 of the distance (300 miles) 210 miles is the answer

Answer 10

G - 210 miles

Hope you try to understand how to get it rather then just put the number down on your paper:

let the meeting point "M" is x miles from B

therefore "M" is 300-x miles from A

Note that time for train A from A to M equals time for train B from B to M.

time = distance / speed

time for train A = (300-x) / 30

time for train B = x / 70

Now, time for train A = time for trian B

(300-x) / 30 = x  / 70

21000 - 70x = 30x

100x = 21000

x = 210

Answer 11

I think it is 90 miles? not sure.

Answer 12

h 150 miles

Answer 13

G 210 miles