Answer:
Approximately 9.211 times
Step-by-step explanation:
Given
--- half life of helium-5
--- half life of helium-9
Required
How many times greater is y than x
To do this, we simply divide y by x


Apply law of indices





Answer:
c
Step-by-step explanation:
There is 6 students in the 8hr zone.
Gosh, do I have to explain? A is a, c is c!
4+6+6+6.5+6.5+6.5+6.5+7+7+7+7+7.5+7.5+7.5+8+8+8+8+8+8.5=141.
141÷20=7.05. So, no, it is not b.
I think it is D intersecting
The word probability has 11 letters, there are 2 b's, so, the probability you are asking for is P= 2/11.
Multiply first equation by 8,
24x + 40y = 352
Multiply second equation by 3,
24x - 21y = -75
Now, subtract second from 1st,
61y = 427
y = 427/61
y = 7
Substitute it in very first equation,
3x + 5(7) = 44
3x = 44 - 35
x = 9 / 3
x =3
In short, Your Answer would be Option D) (3, 7)
Hope this helps!