Question

find the sum of first 50 terms of A.P=5,10,15,20​

Answer 1

Answer:

6375

Step-by-step explanation:

a=5

d=10-5=5

n=50

S50=50/2{2×5+(50-1)5}

=25{10+49×5)

=25{10+245}

=25×255=6375

Answer 2

Answer:

Step-by-Step Explanation

a=5

d=5

n=50

S=?

Now as we know

an=a+(n-1)d

a50=5+(50-1)5

a50=5+(49)5

a50=5+245

a50=250

Now

l=250

Now we know that

Sn=n/2*(a+l)

S50=50/2*(5+250)

S50=25*(255)

S50=6375

I hope that it will help you