Julie and eric row their boat (at a constant speed) 18 miles downstream for 3 hours by the current. rowing at the same rate, the trip back against the current takes 6 hours. find the rate of the boat in still water.

Answer

Find out the the rate of the boat in still water.

To proof

let us assume that the speed of the boat in the still water = u

let us assume that the speed of the current = v

Formula

As given

18 miles downstream for 3 hours

Now for the downstream

u + v = 6

now for the upstream

As given

the trip back against the current takes 6 hours

u-v = 3

Than the two equation becomes

u + v = 6 and u - v = 3

add both the above equation

we get

2u = 9

u = 4.5miles per hour

put this in the  u - v = 3

4.5 -v = 3

v =1.5 miles per hour

The rate of  the boat in the still water is  4.5miles per hour .

Hence proved

answer: the first one

step-by-step explanation: use a calculator and divide the minutes by the dollars.

the total estimated nappy use.=10,500,000

step-by-step explanation:

given that on an average the average baby uses 3528 napkins.

in a particular year 2014, the number of births were 299697 in new south wales.

rounding off the number of births to the nearest hundred thousand we have

no of birtsh = 300000

also rounding off the average usage to nearst thousand we get

average use of a baby = 3500

hence total number of nappy estimated to be used = 3500x300000

= 10,500,000

answer is 10,500,000 nappies