Question

In this particular arithmetic sequence, a8 = 45 and a16 = 93. What is the value of a24?

Answer 1

A24 = 141,

using equation,
an = a1 + (n-1)d,

a8 = a + 7d = 45
a16 = a + 15d = 93

solve simultaneously for values a and d, where a = 3, and d = 6.

therefore, inserting values into a24 eqn, where
a24 = 3 + (24-1)(6) = 141.