Answer:
The second one
210 lbs
Step-by-step explanation:
The difference between 7 and 4 is 3
90/3 = 30
30 times 7 = 210
To find the answer, use
, and then use the equation
To find it's half life.
See the attached picture:
Given:
Circle C and circle R are similar.
The length of arc AB is 
The radius of circle C (AC) = 4 unit
The radius of circle R (QR) =6 unit
To find the length of arc QP.
Formula
The relation between s, r and
is

where,
s be the length of the arc
r be the radius
be the angle.
Now,
For circle C
Taking r = 4
According to the problem,

or,
[ eliminating
from both side]
or, 
or, 
Again,
For circle R
Taking, r = 6 and
we get,
The length of arc QP is

or, 
Hence,
The length of QP is
. Option C.
Answer:
The two circles centered at point A are concentric and similar.