Amotorboat takes 40 minutes to travel 20 miles downstream. the return trip takes 60 minutes. what is the speed of the current?

The current is 5 mph

Step-by-step explanation:

The current helps the boat going down stream and hinders going up so it adds to the speed downstream and subtracts going up.

speed downstream is 20miles/40minutes =1 mi per 2 min. Or 30 mph

Speed upstream is  

20 miles/ 60 minutes = 1 mile per 3minutes or 20 mph

So if the speed of the boat is the same (s) then downstream the boat travels  

S+c =30 mph and s-c =20mph upstream if c is tge current speed

So s=30-c and s=20+c  

So. 30-C=20+c

      10=2C

       5=C

The current is 5 mph

not enough information

step-by-step explanation:

we cannot know this, because the other students could have handed out 10 flyers, or they could have handed out 100. one way, the mean would go up, and another way, the mean would go down.

since your problem is x^4 = 81, what you have to undeo is the "to the fourth power" part.

the inverse (opposite operation) of "to the fourth power" is "to the fourth root".

  (x^4) ^ ¼   = 81 ^ ¼  

  81 = 3^4     so (3 ^ 4) ^ ¼   =   3 ^ 1   = 3

by hand: (3 ^ 4) ^ ¼   =   3 ^ (4 x ¼) = 3 ^ 1   = 3   (when you take a power to a power, multiply the exponents.)

or, do it by calculator. one way of finding the fourth root is to use ^ (1/4)

step-by-step explanation: