Respuesta :

Answer: 7038        Brainliest please.

Step-by-step explanation:

to find : n

tn=a + [(n-1)d]

204=3+(n-1) 3

204-3= 3n- 3

201=3n-3

201+3=3n

204=3n

n=204/3

n =68

As we know

Sn=n/2(t1+tn)

Sn=68/2(3+204)

34(207)

7038