A telecom company charges \(₹890\) for a certain recharge scheme. This prepaid balance is reduced by \(₹15\) each day after the recharge.
(i) Write an equation that models the remaining balance \(b(x)\) after using the scheme for \(x\) days. Explain why it represents linear decay.
(ii) After how many days will the balance run out?
Answer:
(i)Linear expression
It represents linear decay because the prepaid balance at a constant rate of \(₹15\) each day after the recharge, which creates a straight-line pattern when graphed.
(ii) \(\text{The balance will run out after} =\) \(\text{days}\)
[NOTE: Round number of days into nearest integer]