18 boxes = 72% of the total number.
let the total number be x.
72% of the total number = 18
(72/100)*x = 18
0.72x = 18
x = 18/0.72
x = 25
So she had to pack 25 boxes. Option A.
Hope this explains it.
Answer:
math
Step-by-step explanation:
math
This is just a geometric sequence with a sum of:
s(n)=a(1-r^n)/(1-r), a=initial term, r=common ration, n=term number
The rate here is 40% which is 0.4 and a=75 meters so
s(n)=75(1-0.4^n)/(1-0.4)
Notice how when n approaches infinity the number becomes just a(1-0), which gives you:
s(n)=75/(1-0.4)
This is a general solution whenever the rate squared is less than 1, the sum of the infinite series will always be:
s(n)=a/(1-r)
So in this case we have:
s(n)=75(1-0.4)
s(n)=75/0.6
s(n)=125 meters.
The sampling method that is most bias is:
B.
<span>The manager sends an email to 20 customers who buy lumber from the mill, asking each how many of the boards they bought the past week were defective. Results from the first 5 customers to respond are tallied.
</span>C.
<span>On 1 day, an hour after the sawmill begins production, 30 boards in a row are selected and examined.</span>