A speed boat went up the Mississippi River at a speed of 40 mph. It then turned around and traveled downstream to the original starting point at a speed of 60 mph. What was the boat’s average speed? (hint: the answer is NOT 50 mph)

let distance between the two stops be d

so

avg. speed for whole journey = total distance/total time

= ( 2d) / ( d/40 + d/50)

= 2/ (1/40+1/50)

= 2 / ( 90/ 200)

= 2× 200/90

= 40/9 mph

/

step-by-step explanation:

0.0076, if you meant 4.125 divided by 0.03125 it would be 132

step-by-step explanation:

first you have to move the decimal in 0.03125 over until its behind the 5 which is 5 places over. now the number is 3125

then you have to move the decimal in 4.125, 5 places over. now the number is 4,112,500.

now you divide like you would normally would and get 0.0076