Question 204527
1.  First add the two speeds together
{{{850+750 = 1600}}}
- so a combined speed of 1600kph
- Now find how long it will take to travel 4000km
{{{((4000km)/1)* ((1h)/(1600km)) = 2.5h}}}
- And your answer is 2.5 hours
---Check---
{{{850*2.5+750*2.5 = 4000}}}
{{{2125+1875 = 4000}}}
{{{4000=4000}}} Correct

2. To find the speed or rate of the ship we need two things, distance traveled and the time taken to travel that distance given by the equation
{{{S=D/t}}} (where S=speed, D=distance, and t=time)
a. First we'll find the distance traveled
- the plane reached the ship in 1.5 hours at a speed of 180mph
- {{{((1.5h)/1)*((180mi)/(1h)) = 270mi}}}
- So we know now the distance that the plane traveled which is also the distance the boat traveled which is 270mi
b. Now we find the amount of time which the boat took to travel that far
- The boat left 8.5 hours before the plane left and continued to travel for 1.5 hours while the plane was catching up
- {{{8.5+1.5 = 10hours}}}
- So the boat was traveling for 10 hours
c. Now we simply plug the values into the formula
- {{{S=(270mi)/(10h)}}}
- {{{S=27mph}}}
- So the boat traveled at a speed of 27mph
---Check---
-Plane-
{{{((180mi)/(1h))*(1.5h) = 270mi}}}
{{{270mi=270mi}}} Correct
-Ship-
{{{((27mi)/(1h))*(10h) = 270mi}}}
{{{270mi=270mi}}} Correct
-both traveled 270mi so Correct
3. Don't know Rolly's speed...
4. The bus can travel 5 times as fast as Albert can walk
a. The total time traveled is 1 hour
b. because the bus can travel five times as fast as Albert we can say...
{{{B=5A}}} (where B=bus' speed and A=Albert's speed)
c. Going off of that, {{{5/6}}} of the time was spent by Albert walking and {{{1/6}}} of the time was spent on the bus because {{{(1/6)*5 = 5/6}}}
d. The total time traveled was 1 hour and based on the above statement then .8333 hours was spent walking and .1666 hours ws spent on the bus
e. From here you can use the bus' speed or Albert's but i'll use both to check my answer
- {{{(.8333h)*((6km)/(1h)) = 5km}}}
- so Albert walked 5 km
- {{{(.1666h)*((30km)*(1h)) = 5km}}}
- so the bus also traveled 5 km
f. So both traveled 5km which means that 5km is indeed correct
g. Answer: Albert walked 5km