Answer:
a3 + b3 = -7
Step-by-step explanation:
When the sequence is A.P
a1 =4 and a2= -2
Common difference,d = a2 - a1
= -2 - 4
d = -6
a3 = third term
a3 = a1 + 2d
= 4 + 2(-6)
= 4 - 12
= -8
a3 = -8
When the sequence is geometric
a1 =4 and a2= -2
Common ratio, r = a2/a1
= -2/4
r = -1/2
Or
r = -0.5
b3 = third term
b3 = ar²
= 4 * (-1/2)²
= 4 * 1/4
= 4/4
= 1
b3 = 1
a3 + b3 = -8 + 1
= -7
a3 + b3 = -7
Answer is 21.4 %
Used a probability tree diagram.
Um there needs to be another equation
