Answer:
Speed of boat in still water is 6km/h
Speed of current is 4km/h
Step-by-step explanation:
We know speed = distance / time
Let the speed of boat in still water be x
Let the speed of current be y
Hence the speed of boat, down stream = 
Distance downstream = 20km
Time taken = 2 hours
We have

......(1)
Speed of boat upstream = 
Distance upstream = 4
Time taken = 2
We have

...(2)
Adding (1) & (2)


Substituting in (1) we get

Answer:
48 units
Step-by-step explanation:
36 is 75% of what number
36 = .75n
n = 36/.75
n = 48
Answer:
9/40
Step-by-step explanation:
To find the price per can, we take the cost and divide by the number of cans
$5.40/24
5.4/24
Since there is a decimal in the numerator, multiply the top and bottom by 10
5.4/24 * 10/10
54/240
Divide the top and bottom by 6
9/40
First you would take 321 and subtract 5
316
they you would divide by 2
158
there are 158 boys
to find the # of girls take 158 and add 5
163