Question

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for brainlist and 20 thanks give all the other answer in my id
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Answer 1

Step-by-step explanation:

Q.1. a=5

68=5+(n-1)×3

68=3n+2

n=66/3

n= 22

Q.2

Given, S1=2

S2=12

S3=36

t2=12-2=10

t2=10

Q.3

Given, d= -10

12=a+3d

a=30+12

Therefore, a= 42

Hope it helps. Mark as Brainliest.