Illustration of a number line representing an arithmetic progression. It begins at 7, with the 2nd term doubled to arrive at the 10th term. The 19th term is highlighted and connected to the other terms through a consistent difference.

given that the first term of an Ap is 7 and its 10th term is twice the second term calculate the 19th term.

a = 7

a+9d = 2(a+d)
9d +a = 2a+ 2d
7d = a
7d=7
d=1

19th term = a+18d =7+18(1) = 25

a=7,a+9d=2(a+d),9d+a=2a+2d,7d=9,7d= 7,d=1,19th term=a+18d=7+18(1)=25

Sum of 28 terms

19th term =25

Sum of the 28th term=574

14

Good

ALSO SUM OF 28TH