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A.n.=78

a=3

d=5

find =n

A.n = a+d(n-1)

78 =3+5(n-1)

78-3=5(n-1)

75/5=n-1

15+1=n

n=16

a=3

d=5

find =n

A.n = a+d(n-1)

78 =3+5(n-1)

78-3=5(n-1)

75/5=n-1

15+1=n

n=16

d=a2-a1

d=8-3

d=5

an=a+(n-1)d

78=3+(n-1)5

78-3=(n-1)5

75/5=(n-1)

15+1=n

n=16

therfore 78 is the