Sagot :
Answer:
142500
Step-by-step explanation:
i used arithmetic sequence calculator
pabrainliest naman po

Answer:
142500
Step-by-step explanation:
Sn=(n/2)[2a1+(n-1)(d)], with n=60 terms
Sn=(60/2)[2(15)+(60-1)(80)]
Sn=(30)[30+(59)(80)]
Sn=(30)[30+4720]
Sn=(30)(4750)
Sn=142500