8.  a tourist boat is used for sightseeing in a nearby river. the boat travels 2.4 miles downstream and in the same amount of time, it travels 1.8 miles upstream. if the boat travels at an average speed of 21 miles per hour in the still water, find the current of the river.

  3 mph

Step-by-step explanation:

Let c represent the current of the river in miles per hour. Then the ratio of speed downstream to speed upstream is ...

  (21 +c)/(21 -c) = 2.4/1.8

  1.8(21 +c) = 2.4(21 -c) . . . . . . multiply by 1.8(21-c)

  37.8 + 1.8c = 50.4 -2.4c . . . . eliminate parentheses

  4.2c = 12.6 . . . . . . . . . . . . . . . add 2.4c-37.8

  c = 3 . . . . . . . . . . . . . . . . . . . .divide by 4.2

The current of the river is 3 miles per hour.

3 1/3 x 2 3/5 = 8 2/3

step-by-step explanation:

just multiply the first number by the second number to get your answer.

i dont know if you cant find a way its best to actually add all of them start from 105 tho

step-by-step explanation: