Question

Find the sum of first 30 terms.of ap whose 2nd term is 2 and 17 term is 22

Answer 1

Answer:

600= sum of first 30 ap

Step-by-step explanation:

a+(2-1)d=2 (given )

a+(17-1)d=22 (given)

a+d=2 ie. a=2-d

a+16d=22 2-d+16d=22

15d=20 d=4/3 a=2-4/3=2/3

a=2/3 d=4/3

sum of first 30 ap is=

30/2[2(2/3)+(30-1)4/3]

=15[4/3+29(4/3)]

=5(4+116)=5×120=600

hope it helps you thanks