Question

which term of the AP:2.9,3.2,3.5,.... is 8?

Answer 1

$8 = 2.9 + (n - 1)0.3 \\ (n - 1) .3 = 8 - 2.9 \\ n - 1 = 5.1 \div 0.3 \\ n = 17 + 1 = 18$