Question

Troy signed up for a new cell phone which charges him a fee of $40 per month ,plus $0.05 for each text message (t) that he sends.If Troy wants to spend at most $70 on his cell phone this month .what is the inequality?

Answer 1

If each text messages costs 0.05, and the number of text messages is t, the total cost Troy will have to pay is the fixed cost of 40 plus the variable cost of 0.05 per message, so we have:

$\text{cost}=40+0.05t$

If Troy wants to spend at most 70, the cost needs to be lesser than or equal 70, so we have that:

$\begin{gathered} \text{cost}\le70 \\ 40+0.05t\le70 \end{gathered}$

So the inequality is 40 + 0.05t <= 70