A salesman made a trip of 420 miles by bus and train. He traveled 3 hours by bus and 5 hours by train. If the train averaged 12 mph more than the bus, find the rate of each.

The speed at which the buss made the trip was 45 mph and the train was 57 mph.

Step-by-step explanation:

The average speed is given by:

speed = distance / time

Therefore we can manipulate it to give us the distance:

distance = speed*time

The time distance of each stage of his trip summed must be equal to the total distance of the trip. Since he made a trip in two legs, one by bus that lasted 3 h at a speed of "x" and one that lasted 5 hours at a speed of "x + 12". We have:

420 = 3*x + 5*(x + 12)

3*x + 5*(x + 12) = 420

3*x + 5*x + 60 = 420

8*x = 420 - 60

8*x = 360

x = 45 mph

The speed at which the buss made the trip was 45 mph and the train was 57 mph.

3

step-by-step explanation:

in standard form:

a= dictionaries

b= maps

you have to buy 3 dictionaries, so put a 3 next to the a (dictionaries) so that you can multiply them by each other.

a3+b= 60 (the amount of money you have)

we already know the cost of a=15 so replace a with $15

($15 x 3)+b=60

multiply 15 and 3 to get $45 and replace it with $45

45+b=60

and then replace b with 15 to get the total:

45+15=60

that means you have $15 left after buying 3 dictionaries.

15 divided by the cost of a map ($5) equals 3.

so you can buy 3 maps.

sorry if it was confusing!