Answer:
its 706.5
Step-by-step explanation:
do pi r^2
pi is 3.14
radius is 15
15 times 15 times 3.15 is 706.5
hope this helps
Corrected Question
Sue travels by bus or walks when she visits the shops. The probability that she catches the bus to the shops is 0.4. The probability she catches the bus from the shops is 0.7. Show the probability that Sue walks at one way is 0.72
Answer:
(Proved)
Step-by-step explanation:
Sue travels by bus or walks when she visits the shops.
Let the event that she catches the bus to the shop=A
Let the event that she catches the bus from the shop=B
P(A)=0.4
P(B)=0.7
Both A and B are independent events.
Therefore,Probability that she catches the bus to and from the shop:
P(A∩B) = 0.4 X 0.7= 0.28
Probability Sue walks at least one way 
Hence, the probability that Sue walks at least one way is 0.72.
Solving a system of equations we will see that we need to use <u>40 liters of the 80% acid solution</u>, and the other <u>20 liters are of the 35% acid solution</u>.
<h3>
How many liters of each solution do we need to use?</h3>
First, we need to define the variables:
- x = liters of the 35% acid used.
- y = liters of the 80% acid used.
We know that we want to produce 60 liters of 65% acid, then we have the system of equations:
x + y = 60
x*0.35 + y*0.80 = 60*0.65
(in the second equation we wrote the percentages in decimal form).
To solve this we need to isolate one of the variables in one equation and then replace it in other one, isolating x we get:
x = 60 - y
Replacing that in the other equation:
(60 - y)*0.35 + y*0.80 = 60*0.65
y*(0.80 - 0.35) = 60*(0.65 - 0.35)
y*0.45 = 60*0.30
y = 60*0.30/0.45 = 40
So we need to use <u>40 liters of the 80% acid solution</u>, and the other <u>20 liters are of the 35% acid solution</u>.
If you want to learn more about systems of equations:
brainly.com/question/13729904
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