Question

The table shows how the number of sit-ups Marla does each day has changed over time. At this rate, how many sit-ups will she do on Day 12? Explain your steps in solving this problem.

Answer 1

To determine the number sit-ups Marla will do on day 12;

The number is arithmetic sequence;

$\begin{gathered} 17,21,25,29,33 \\ a_1=17,\text{ d=4, n=12 and a}_{12}=? \end{gathered}$

$a_n=a_1+(n-1)d$$a_{12}=17+11(4)=17+44=61$

The answer is 61.