The student would have to score 100% on their next test to brung their average up to 90. Here is why;
90+84+86=260
(260+?)/4=90
(260+100)/4=90
360/4=90
This is done to get the mean (or average) of a group of numbers by adding all the numbers and dividing by the amount of numbers you added together. Here it is divided by 4 because of the three tests he has taken and the test he will take.
Answer:
5'3
Step-by-step explanation:
trust me I know what im talking about
Multiply both sides by 15.
s = 0.88 * 15 = 13.2 (use calculator)
V=B*h
To double the volume , we have to double the height
then V2=B*2h=2*V
Answer: 41.5 min
Step-by-step explanation:
This problem can be solved with the Radioactive Half Life Formula:
(1)
Where:
is the final amount of the radioactive element
is the initial amount of the radioactive element
is the time elapsed
is the half life of the radioactive element
So, we need to substitute the given values and find from (1):
(2)
(3)
(4)
Applying natural logarithm in both sides:
(5)
(6)
Clearing :
This is the time elapsed
