Answer:94%
Step-by-step explanation:
Half life of a radioactive element is the time taken for half it's mass to disintegrate away.it means after attaining half life,what will be left is 100-50=50%.
Let the 100% mass of C-14,be x
Then 5730years=1/2 of X
Then 660 years=y of X
Where Y is the fraction of C-14 that has disintegrate as at 1988.
5730/660=1/2X/yX
5730/660=1/2/y
Cross multiplying
5730×y=660×1/2
5730y=330
Y=330/5730=0.05759
In %,5.76%
Amount of C-14 left is
100-5.76=94.24=94% as at 1988.
Answer: The spelling questions are 10, while the vocab questions are 16.
Step-by-step explanation: Let the spelling questions be represented by letter p, while the vocab questions should be represented by v. If there is a total of 16 questions as stated, then p + v = 26
Also if there are a total of 100 points obtainable in the test, then spelling questions times 2 points (2p) plus vocab questions times 5 points (5v) equals 100 points. This can be expressed as 2p + 5v = 100
We now have a pair of simultaneous equations as follows
p + v = 26 ———(1)
2p + 5v = 100 ———(2)
Make p the subject of the equation in equation (1). p = 26 - v. Next substitute for the value of p into equation (2)
2(26 - v) + 5v = 100
52 - 2v + 5v = 100
We collect like terms and we have
5v - 2v = 100 - 52
3v = 48
Divide both sides of the equation by 3
v = 16
Now having calculated v, substitute for the value of v into equation (1)
p + 16 = 26
Subtract 16 from both sides of the equation
p = 10
Therefore, the spelling questions equals 10 in all. While the vocab questions equals 16 in all.
-4x+8z is the combined like terms
Answer:
122 people
Step-by-step explanation:
Subtract 90 from 4500 then divide by 36, i'll save you some time it's 122.5 but you can't have 1/2 a person so you just get 122 people
Hope this helps :-)
Answer:
CE would be half of AD.
Step-by-step explanation:
A, E and D are all points on the circumference of the circle.
AD is the diameter.
CE is the radius.
CE would be half of AD.
