Question

(a) What is 1+ 2+ 3+ ... + 50 ?​

Answer 1

Answer:

a=1

d=2-1=1

l=50

50=a+(n-1)d

50=1+(n-1)1

50-1=(n-1)

49=n-1

50=n

Sum of 50 terms=(n/2)×(1+50)

=(50/2)×51

=25×51

=1275