Question

what is the 15th term of the sequence: 7, 14, 21...? 105 100 110 115

Explanation:

Step1: Identify sequence type & formula

This is an arithmetic sequence. The nth term formula is $a_n = a_1 + (n-1)d$, where $a_1$ is the first term, $n$ is the term number, and $d$ is the common difference.

Step2: Define values from the sequence

$a_1 = 7$, $d = 14 - 7 = 7$, $n = 15$

Step3: Substitute into the formula

$a_{15} = 7 + (15-1) \times 7$

Step4: Simplify the expression

$a_{15} = 7 + 14 \times 7 = 7 + 98 = 105$

Answer:

A. 105