Question

the sum of all the intergers between 50 and 350 ends with 5 is​

Answer 1

Answer:

6000

Step-by-step explanation:

the starting number ending with 5 is 55

and ending number is 345

so the series 55,65,75,...345

it is in ap

with a=55

d=10

an=345

an= a+(n-1)d

345=55+(n-1)10

345-55=10(n-1)

10(n-1)=290

n-1=29

n=30

so s30 =(n/2)(a+l)

= 15*(55+345)

= 15*400

=6000