The correct answer should be :
Option 3 : 
Hope this helps,
Davinia.
Answer:
b1 = 2 ; r = 3
Step-by-step explanation:
Given that :
if b3 −b1 = 16 and b5 −b3 = 144.
For a geometric series :
Ist term = a
Second term = ar
3rd term = ar^2
4th term = ar^3
5th term = ar^4 ;...
If b3 - b1 = 16;
ar^2 - a = 16
a(r^2 - 1) = 16 - - - (1)
b5 - b3 = 144
ar^4 - ar^2 = 144
ar^2(r^2 - 1) = 144 - - - - (2)
Divide (1) by (2)
a(r^2 - 1) / ar^2(r^2 - 1) = 16 /144
a / ar^2 = 1 / 9
ar^2 = 9a
Substitute for a in ar^2 - a = 16
9a - a = 16
8a = 16
a = 2
From ar^2 - a = 16
2r^2 - 2 = 16
2r^2 = 16 + 2
2r^2 = 18
r^2 = 18 / 2
r^2 = 9
r = √9
r = 3
Hence ;
a = b1 = 2 ; r = 3
Answer:
a) 0.54 = 54% probability that a randomly selected person will feel guilty for either wasting food or leaving lights on when not in a room or both.
b) 0.46 = 46% probability that a randomly selected person will not feel guilty for either of these reasons
Step-by-step explanation:
We use Venn's Equations for probabilities.
I am going to say that:
P(A) is the probability that a randomly selected person will feel guilty about wasting food.
P(B) is the probability that a randomly selected person will feel guilty about leaving lights on when not in a room.
0.12 probability that a randomly selected person will feel guilty for both of these reasons.
This means that 
0.27 probability that a randomly selected person will feel guilty about leaving lights on when not in a room.
This means that 
0.39 probability that a randomly selected person will feel guilty about wasting food
This means that 
a. What is the probability that a randomly selected person will feel guilty for either wasting food or leaving lights on when not in a room or both (to 2 decimals)?

0.54 = 54% probability that a randomly selected person will feel guilty for either wasting food or leaving lights on when not in a room or both.
b. What is the probability that a randomly selected person will not feel guilty for either of these reasons (to 2 decimals)?

0.46 = 46% probability that a randomly selected person will not feel guilty for either of these reasons