Let speed of the boat in still water = x miles per hour
Let speed of the current = y miles per hour
When water and current both flow in same direction then effective speed will be sum of both speeds that is (x+y)
now plug the given values in formula speed=distance/time
we get equation:
(x+y)=160/8
or x+y=20...(i)
When water and current both flow in opposite direction then effective speed will be difference of both speeds that is (x-y)
now plug the given values in formula speed=distance/time
we get equation:
(x-y)=160/40
or x-y=4
or x=4+y...(ii)
plug value of x into (i)
4+y+y=20
4+2y=20
2y=16
y=8
plug value of y into (ii)
x=4+8=12
Hence final answer is given by:
Speed of the boat in still water = 12 miles per hour
Speed of the current = 8 miles per hour
Answer:
a) 
D. 9.74
b) 
B. 74
Step-by-step explanation:
Part a
We have the following dataset given:
69 74 75 62 70 93 64 69 61 88 67 77 87 90 66 91 77 63 82 82 71 74 76 65 83
We can begin calculating the sample mean with the following formula:

And replacing we got:

Now we can calculate the sample deviation with the following formula:

And after replace we got:

Part b
For this case we need to sort the value on increasing way:
[1] 61 62 63 64 65 66 67 69 69 70 71 74 74 75 76 77 77 82 82 83 87 88 90 91 93
And the median would be the value in the position 13 and we got:

Answer:
That's easy 2/5
Step-by-step explanation:
Half of 5 is 2.5 and well ovbi 2 is less than 2.5 therefore 2/5 is lees than a half
Hope this helps!
Answer:
375
Step-by-step explanation:
12.5=1min
30min=?
30x12.5=357
Answer:
39
Step-by-step explanation:
1190 + 2125 = 3315 (number of beads)
3315/85 = 36 (number of bracelets jasmine can make)