Question

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Answer 1

Question 1

`a=1, r=1/2 \implies S_(\infty)=(1)/(1-(1/2))=\boxed{2}`

Question 2

`d=10, a_1+5d=52 \implies a_1=2 \\ \\ a_(15)=a_1+14d=2+14(10)=\boxed{142}`