|
Question 933827: An eastbound train leaves Vancouver for Toronto, a distance of about 4370 km, travelling at about 90km/h. At the same time a west bound train leaves Toronto to Vancouver travelling at about 70 km/h. How far from Toronto are the trains when they pass each other? For how long have they been travelling when this happens?
How much pure water bust be mixed with 9 pints of 50% developer to produce a mixture that is 28% developer?
Answer by lwsshak3(11628)   (Show Source):
You can put this solution on YOUR website! An eastbound train leaves Vancouver for Toronto, a distance of about 4370 km, travelling at about 90km/h. At the same time a west bound train leaves Toronto to Vancouver travelling at about 70 km/h. How far from Toronto are the trains when they pass each other? For how long have they been travelling when this happens?
***
let x=length of time trains had been traveling
let d=distance from Toronto when trains pass each other
travel time=distance/speed
speed=90+70=160 km/h
x=4370/160=27.31
distance=speed*travel time
d=70*x=1911.88
length of time trains had been traveling=27.31 hrs
distance from Toronto when trains pass each other=1911.88 km
..
How much pure water bust be mixed with 9 pints of 50% developer to produce a mixture that is 28% developer?
let x=amt of pure water to be mixed
50%*9=28%(9+x)
4.5=2.52+.28x
.28x=1.98
x=7.07
amt of pure water to be mixed=7.07 pints
|
|
|
| |
