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:
Store B
Step-by-step explanation:
To figure out which store has the better deal, we need to figure out the price per unit. We can do this by dividing the price by the number of the shirts. Store A sells their t-shirts for 8.33 or 8 1/3 dollars per shirt, while Store B sells their shirts for 8 dollars a shirt. 8 < 8 1/3, therefore Store B has the better deal.
If we know that 128 is 74% of something, we can write it like this:
74%x=128.
If we take the percent away (percent means by hundred in latin, 1%=1/100), we'll have
74/100 *x=128
//let's multiply both sides by 100, that way we can get rid of the ugly "/100 because 100/100 = 1, and we can ignore 1 in multiplications
100*74/100 *x = 128 *100// let's simplify the left side: 100/100=1
74*x=128*100// let's calculate the right side now
74*x=12800// now we have to divide both sides by 74
x=12800/74
if we divde this, we have: 172 + 72/74. (why? see below)
We can simplify the fraction by division by 2: 172 36/37
00172
_______
12800:74
-74
___
540
- 518
-------
220
148
_________
72
Answer:
174.50
Step-by-step explanation:
first order the numbers from least to greatest then find the middle digit. if there are two, add them together, then divide them by 2. if there's only one, that is your median.