The percentage of the radioactive isotope left is 25.0000%.
<h3>What is the half life?</h3>
The half life of a radioactive isotope is the time that will elapse before only half of the number of original isotopes will remain.
Now;
We are told that;
Half life (t1/2) = 55 days
Time taken (t) = 115 days
Ratio of isotope remaining = N/No
Thus;
N/No = (1/2)^t/t1/2
N/No = (1/2)^115/55
N/No = (1/2)^2
N/No =1/4
Hence, the percentage = 1/4 * 100/1 = 25.0000%
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Y2-y1/x2-x1 is slope so
9-9/14-(-20) so you get 0/34 which means there is no slope since they have the same y (the equation would be y=0x+9 therefore y=9)
Which makes sense since the equation is a straight line
Volume of the cube = a³ = (14cm)³= 2744 cm³
To find surface are, we need to find at first area of the face
A(face)=14² cm².
Cube has 6 congruent squares, so
Surface area of the cube = 6*14² cm²= 1176 cm²
Answer: The total number of student in the school = 240.
Step-by-step explanation:
Let x be the total number of students in the school.
Given: 35% of the students at Charles drew middle school are 6th graders.
i.e. Number of sixth graders = 35% of x = 0.35x [35% = 0.35]
Since there are 84 sixth graders in the school,
So 
Divide both sides by 0.35, we get

Hence, the total number of student in the school = 240.
Answer:
B.
Step-by-step explanation:
Let's call x the number of pens and y the number of notebooks that Monique can buy.
If each pen costs $2 and each notebook costs $3, so she is going to spend 2*x on pens and she is going to spend 3*y on notebooks.
Additionally, she is going to spend a maximum of $36. so:
2x + 3y
36
It means that the line that separated the region is:
2x + 3y = 36
This is the same that a line that passes for the points (0,12) and (18,0) or the line of the region B